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Ci a ion: Cae ano, H.; Laím, L.;
San iago, A.; Du ães, L.; Shahbazian,
A. De elopmen o Passi e Fi e
P o ec ion Mo a s. Appl. Sci. 2022,
12, 2093. h ps://doi.o g/10.3390/
app12042093
Academic Edi o : Sang-Hyo Kim
Recei ed: 23 Decembe 2021
Accep ed: 7 Feb ua y 2022
Published: 17 Feb ua y 2022
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applied
sciences
A icle
De elopmen o Passi e Fi e P o ec ion Mo a s
Hugo Cae ano 1,* , Luís Laím1, Aldina San iago 1, Luísa Du ães 2and Ashkan Shahbazian 1
1Depa men o Ci il Enginee ing, Uni e si y o Coimb a, ISISE, Rua Luís Reis San os,
3030-790 Coimb a, Po ugal; [email p o ec ed] (L.L.); [email p o ec ed] (A.S.);
[email p o ec ed] (A.S.)
2Depa men o Chemical Enginee ing, Uni e si y o Coimb a, CIEPQPF, Rua Síl io Lima,
3030-790 Coimb a, Po ugal; [email p o ec ed]
*Co espondence: [email p o ec ed]; Tel.:+00351-239-797-261
Abs ac :
Du ing a i e e en , he s abili y o s eel s uc u es may be comp omised, and s uc u al
collapse may occu due o he loss o hei mechanical esis ance as he empe a u e inc eases. One o
he solu ions o educe his p oblem is he p o ec ion wi h a coa ing using enhanced i e- esis an
mo a s. This pape epo s a de ailed expe imen al wo k aiming o de elop gypsum and cemen -
based mo a s o passi e i e p o ec ion and e alua e hei composi ion’s e ec in he inal he mal
pe o mance. Two ypes o specimens we e es ed: (i) small specimens composed o a mo a coa ing
(10 mm hick) and one s eel pla e and (ii) squa e sec ion sho ubula s eel columns wi h 20 mm
o coa ing. The e alua ion o he he mal p o ec ion was ca ied ou by (a) measu ing he he mal
g adien be ween he exposed su ace o he p o ec ed s eel pla e unde high empe a u es and
he mo a -s eel in e ace and (b) assessing he i e esis ance o he sho s eel columns. I was
concluded ha he composi ions wi h gypsum binde p esen be e he mal insula ion han he
cemen i ious composi ions. Addi ionally, he in oduc ion o nano- and mic opa icles o silica s ill
sligh ly imp o ed he he mal insula ion o he es ed composi ions.
Keywo ds:
s eel columns; nano- and mic osilica; gypsum; cemen ; mo a ; passi e i e p o ec ion;
insula ion; i e; hea ans e
1. In oduc ion
The e is a g owing in e es in de eloping al e na i e and sus ainable cons uc ion
ma e ials wi h enhanced p ope ies. As me als a e in ini ely ecyclable, his ype o con-
s uc ion is pa o a u u e o “g een cons uc ion”, hus con ibu ing o a sec o o he
economy wi h low en i onmen al impac [1–3].
Howe e , s eel s uc u es show some weaknesses, especially hei s uc u al beha iou
when subjec ed o i e [
4
–
9
]. Due o he high he mal conduc i i y o he s eel, he high
sec ion ac o o he membe s, and he apid deg ada ion o he s eel mechanical p ope -
ies, wi h he inc ease o s eel empe a u e, apid change in he s i ness and mechanical
esis ance may be no iced in he s uc u e. I s esis ance and s abili y may be comp omised,
leading o he collapse o some elemen s o e en o he en i e s uc u e [10–15].
The he mal p o ec ion o hese s uc u al elemen s is c ucial. The i e p o ec ion o
s uc u es can be achie ed by combining ac i e and passi e i e p o ec ion sys ems and
managemen sys ems (smoke exhaus sys ems, communica ion and e acua ion p ocedu es,
i e de ec ion sys ems, and compa men a ion [
16
]). Ac i e i e p o ec ion can consis o
sys ems o i ems such as i e ex inguishe s, s andpipes, sp inkle sys ems, and i e blan-
ke s [
17
]. I is equi ed ha hese sys ems ha e a quick esponse capaci y in ex inguishing
o con olling he de elopmen o a i e in i s ini ial phase [
18
]. Howe e , implemen ing
hese sys ems has high ins alla ion and main enance cos s, and hei esul s can ha e low
unc ional eliabili y and unsa is ac o y ope a ional esul s [19].
Appl. Sci. 2022,12, 2093. h ps://doi.o g/10.3390/app12042093 h ps://www.mdpi.com/jou nal/applsci
Appl. Sci. 2022,12, 2093 2 o 20
In u n, when applying passi e p o ec ion, i is almos su e ha i will be ope a ional
du ing a i e e en . Passi e sys ems include he i e esis ance o s uc u al o nons uc-
u al membe s o a building, such as columns, beams, walls, and ceilings. This pu pose
ensu es adequa e e acua ion imes, minimum sa e y condi ions o i e igh ing and escue
ope a ions and minimises p ope y, economic, and li e losses [20].
The mos common me hod o p o ec a membe om exposu e o ex eme empe a-
u es is o apply insula ion ma e ials a ound he s uc u al membe s. Insula ion ma e ials
used as i e p o ec ion in s uc u al s eel membe s can be: boa d sys ems (gypsum boa d
o calcium silica e), insula ing blanke s (ce amic, ock, and glass wool), sp ay sys ems, o
in umescen coa ings [
21
]. These ma e ials should be cheape han he s eelwo k, easy o
applica ion, sa e (i.e., no be haza dous du ing he applica ion and in se ice, o oxic in
he e en o i e), and should insula e and emain undamaged du ing he i e a ack (wi h
limi ed de achmen s and ac u es du ing he equi ed i e esis ance) [22].
One solu ion ha mee s hese p o ec ion equi emen s is he coa ing wi h enhanced
i e- esis an mo a s due o he in oduc ion o nanosilica pa icles and he mally s able
and po ous agg ega es [
23
]. Wi h he eme gence o nanoma e ials (silica nanopa icles,
i anium dioxide nanopa icles, alumina nanopa icles, and ca bon nano ubes, e c.), hei
inco po a ion in pas es, mo a s, and o he cemen -based ma e ials has appea ed as a
possibili y o imp o e hei mechanical and he mal p ope ies: highe du abili y, be e
esis ance o co osion and be e i e esis ance [
24
–
28
], wi h he silica nanopa icles being
he mos s udied nanoma e ial in cemen [
26
]. Howe e , li le a en ion has been gi en o
o he p ope ies, such as he mal conduc i i y a ele a ed empe a u es [29].
When subjec ed o high empe a u es, pe li e and e miculi e ha e been inco po a ed
in cemen mo a s o imp o e hei he mal pe o mance [
30
]. Pe li e consis s o a siliceous
olcanic ock wi h 2% o 6% wa e combined. Howe e , when small pe li e g ains a e
subjec ed o high empe a u es (870
◦
C), hey s ongly inc ease hei olume wi h nume ous
iny, sealed ai cells, like popco n gi ing ise o ligh weigh expanded pe li e. Ligh weigh
expanded pe li e has low he mal conduc i i y (0.04–0.06 W/mK), ela i ely high mel ing
poin (1260–1343
◦
C) and low densi y (loose: 50–400 kg/m
3
) [
31
]. These cha ac e is ics
make pe li e a ma e ial wi h excellen insula ing p ope ies.
Ve miculi e consis s o a micalike mine al con aining a shiny lake ( he phyllosilica e
g oup). I is p oduced a ambien condi ions om he wea he ing/hyd o he mal al e a ion
o phlogopi e o bio i e [
30
]. Simila o pe li e, when e miculi e pa icles a e subjec ed
o high empe a u es ( om 650 o 950
◦
C), hey expand, p esen ing a densi y o 80 o
120 kg/m3,
a mel ing poin be ween 1240 o 1430
◦
C and a he mal conduc i i y be ween
0.04 o 0.12 W/mK [
32
]. Mo eo e , due o hei highly po ous s uc u e, hese ma e ials
abso b mois u e in a ying deg ees (depending on hei ype), which when combined wi h
he low he mal conduc i i y, ex ends hei du abili y du ing he i e.
Pe li e may be a be e supplemen han e miculi e, no only due o i s he mal
conduc i i y bu also o he high e ac ion e ec o e miculi e [
33
]. As hey a e ma e ials
wi h good he mal p ope ies, hey can be used in he de elopmen o plas e o cemen
mo a s as a passi e i e p o ec ion solu ion in s eel s uc u es.
In addi ion o cemen , plas e can also be used as a binde and combined wi h pe li e
and/o e miculi e o de elop mo a s o passi e i e p o ec ion. Compa ed o cemen ,
gypsum is much cheape , easie o p oduce, and p o ides a mo e e ec i e he mal ba ie
because i has a lowe he mal conduc i i y han cemen . I also con ibu es o he ene gy
loss om i e due o i s endo he mic dehyd a ion p ocess [34,35].
S udies ha e shown ha pe li e–Po land cemen and pe li e–gypsum coa ings a e he
mos e ec i e plas e s as i e ba ie s and in e a ding he conduc ion o high empe a u es
ac oss hei hickness among di e en kinds o coa ings, such as adi ional-cemen plas e ,
e miculi e cemen /gypsum-based mo a , in umescen coa ing, calcium silica e boa d,
and LECA-cemen plas e [36–38].
The e o e, his pape p esen s he de elopmen o di e en gypsum o cemen -based
mo a s as passi e i e p o ec ion ma e ials, he e alua ion o he in luence o agg ega e
Appl. Sci. 2022,12, 2093 3 o 20
size, and he addi ion o silica mic o- and nanopa icles on hei he mal pe o mance and
assessmen o i e esis ance o he p o ec ed sho s eel columns.
2. Ma e ials and Me hods
2.1. Ma e ials and Composi ions
In a p elimina y phase, se e al mo a s based on cemen o gypsum we e de eloped,
wi h di e en dosages o aw ma e ials, acco ding o he s a e o he a as p esen ed
in he in oduc ion o his pape (Table 1). The ollowing ma e ials we e used in he
composi ions o he mo a s: comme cial passi e p o ec ion solu ions 1 (IGN) and 2
(VER), Po land cemen CEM II/B-L 32.5 (PC), Isidac 40 e ac o y cemen (IRC), Topeca
M40 e ac o y cemen (TRC), Ele oland e ac o y cemen (ERC), gypsum powde (GP),
expanded e miculi e wi h dimensions be ween 0.5 and 3 mm (EV), expanded pe li e wi h
dimensions be ween 1 and 5 mm (EP), polyp opylene ibe s wi h an a e age diame e
o 31
µ
m and an a e age leng h o 6 mm (PP), silica sand wi h dimensions be ween 0.01
and 2.00 mm (SS), expanded clay wi h dimensions be ween 0.01 and 2.00 mm (EC), silica
mic opa icles wi h an a e age diame e o 1000 nm (MS), silica nanopa icles wi h an
a e age diame e o 200 nm (NS), and wa e (W). Silica mic o- and nanopa icles we e
syn hesised in he labo a o y, acco ding o he p ocedu e desc ibed by Vaz-Ramos e al. [
15
].
Table 1. Mo a composi ions de eloped a LEMEC (a) (amoun o ma e ials in olume %).
Mo a
Designa ion
Binde s Type CPPS Agg ega es
NS and MS W/B
PC ERC IRC TRC GP IGN VER SS EV EP EC PP/B
C_1 30% - - - - - - 70% - - - - - 0.50
C_2 29% - - - - - - 70% - - - 1% - 0.50
C_3 28% - - - - - - 70% - - - 1% 1% 0.50
C_4 26% - - - - - - 70% - - - 1% 3% 0.50
C_5 23% - - - - - - 70% - - - 1% 6% 0.50
C_6 29% - - - - - - - - 70% - 1% - 0.50
C_7 29% - - - - - - 35% 35% - - 1% - 0.50
C_8 29% - - - - - - - - - 70% 1% - 0.50
C_9 - 30% - - - - - 70% - - - - - 0.50
C_10 - 29% - - - - - 70% - - - 1% - 0.70
C_11 - 29% - - - - - - - 70% - 1% - 0.70
C_12 - 29% - - - - - 35% 35% - - 1% - 0.70
C_13 - - 30% - - - - 70% - - - - - 0.50
C_14 - - 29% - - - - 70% - - - 1% - 0.70
C_15 - - 29% - - - - - - 70% - 1% - 0.70
C_16 - - 29% - - - - 35% 35% - - 1% - 0.70
C_17 - - - - - 100% - - - - - - - 0.50
C_18 - - - - - 100% - - - - - - - 0.60
C_19 - - - - - 99% - - - - - 1% - 0.70
C_20 - - - 100% - - - - - - - - - 0.50
C_21 - - - 100% - - - - - - - - - 0.70
C_22 - - - 99% - - - - - - - 1% - 0.70
C_23 - - - - - 80% - - 20% - - - - 0.70
C_24 - - - - - 99% - - - - - 1% - 0.70
C_25 - - - - - - 100% - - - - - - 0.50
C_26 - - - - - - 100% - - - - - - 0,60
C_27 - - - - - - 100% - - - - - - 0.70
C_28 - - - - - - 99% - - - - 1% - 0.60
C_29 49% - - - - - - - - 50% - 1% - 1.30
C_30 49% - - - - - - - 50% - - 1% - 3.21
C_31 50% - - - - - - - 25% 25% - - - 2.17
C_32 49% - - - - - - - 25% 25% - 1% - 2.17
C_33 - - - - 100% - - - - - - - - 0.50
C_34 - - - - 100% - - - - - - - - 0.50
C_35 - - - - 100% - - - - - - - - 0.60
C_36 - - - - 40% - - - - 60% - - - 1.25
C_37 - - - - 50% - - - - 50% - - - 1.00
C_38 - - - - 60% - - - - 40% - - - 0.83
C_39 - - - - 40% - - - 60% - - - - 2.10
C_40 - - - - 50% - - - 50% - - - - 1.60
C_41 - - - - 60% - - - 40% - - - - 1.25
C_42 - - - - 20% - - - 40% 40% - - - 3.75
C_43 - - - - 30% - - - 35% 35% - - - 2.50
C_44 - - - - 40% - - - 30% 30% - - - 2.15
C_45 - - - - 99.5% - - - - - - 0.5% - 0.50
C_46 - - - - 99% - - - - - - 1% - 0.50
C_47 - - - - 98.5% - - - - - - 1.5% - 0.50
C_48 - 20% - - - - - - 40% 40% - - - 2.75
(a) Labo a o y o Tes ing Ma e ials and S uc u es o Uni e si y o Coimb a.
Appl. Sci. 2022,12, 2093 4 o 20
Tes ing wo comme cial passi e p o ec ion solu ions es ed, i was possible o iden i y
he comme cial solu ion ha p o ided one o he bes he mal insula ion esul s, which
came o be conside ed as he e e ence mo a (CM). F om he p elimina y es s phase, ou
di e en mo a s we e selec ed (DCM, DGMP, DGMV, and DRCM) om o y di e en
mo a s de eloped wi h g ea e he mal insula ion capaci y han ha p o ided by he
e e ence mo a . As can be seen in Table 2, he DCM was made wi h Po land cemen ,
e miculi e and polyp opylene ibe s, he DGMP was p epa ed gypsum and pe li e, he
DGMV was made o gypsum and e miculi e and he DRCM was p epa ed wi h e ac o y
cemen , pe li e, and e miculi e.
Table 2. Cons i u ion o each selec ed mo a (amoun o ma e ials in olume %).
Mo a Designa ion CPPS PC RC GP EV EP PP/B W/B
CM 100% - - - - - - 0.60 *
DCM - 49% - - 50% - 1% 3.21
DGMP - - - 40% - 60% - 1.21
DGMV - - - 50% 50% - - 2.10
DRCM - - 50% - 25% 25% - 2.75
* Wa e comme cial solu ion a io in weigh %.
To analyze he in luence o expanded pe li e and expanded e miculi e g ain size on
he he mal pe o mance o labo a o y de eloped mo a s, wo di e en g inding me hods
we e used: Los Angeles (LA) and Indus ial Mill (IM). The i s me hod was ca ied ou
using he Los Angeles me hod, which agmen ed he agg ega e by ab asion and shock
using s eel balls. The pa icle size o hese aw ma e ials was assessed using a pa icle
size analysis (speci ica ion LNEC E 195-1966), and i was obse ed ha hei size anged
om 0.075 o 0.85 mm. The second me hod was ca ied ou using an indus ial mill,
which by he ic ion o he agg ega e wi h he d um signi ican ly educed he size o i s
pa icles compa ed o he LA me hod. The pa icle size analysis iden i ied a pa icle size
anging om 0.025 o 0.40 mm. Finally, di e en dosages o silica mic o and nanopa icles
we e added and es ed in DCM, DGMP, DGMV, and DRCM o assess hei in luence on
he he mal insula ion o he espec i e mo a s, as desc ibed in he ollowing sec ion o
he pape .
2.2. Expe imen al P og am
The expe imen al p og am included wo di e en ypes o es s, depending on he
ype o specimens: s eel pla e (SP) (Table 3) and squa e sec ion sho s eel columns (SSC)
(Table 4). The expe imen al p og am o es s on SP included i e di e en mo a (CM,
DCM, DGMP, DGMV, and DRCM), and 45 specimens we e p oduced. Each se o h ee
specimens used in hei he mal es s was used o ob ain be e eliabili y o esul s.
Table 3. Expe imen al p og am on s eel pla e specimens.
Mo a
Designa ion
Wi hou NS and MS Wi h NS and MS To al No. o
Specimens
LA Me hod IM Me hod LA Me hod IM Me hod
CM 3 (*) (*) (*)
45
DCM 3 3 3 3
DGMP 3 3 3 3
DGMV 3 3 3 3
DRCM 3 3 (**) (**)
(*) The comme cial solu ion was no modi ied, so he e was no need o es mo e han h ee specimens. (**) Since
his mo a has he wo s esul s, i has no been es ed wi h he addi ion o silica mic o- and nanopa icles.
Appl. Sci. 2022,12, 2093 5 o 20
Table 4. Expe imen al p og am on sho s eel columns.
Di e en Types o Tes ed Columns Specimens
Designa ion
Numbe o
Repe i ions
To al No. o
Specimens
Columns wi hou passi e
i e p o ec ion
SSC1 2
12
SSC2
Columns coa ed wi h CM SSC3 2
SSC4
Column coa ed
wi h DCM
Wi hou MS and NS SSC5 2
SSC6
Wi h MS and NS SSC11 2
SSC14
Column coa ed
wi h DGMP
Wi hou MS and NS SSC7 2
SSC8
Wi h MS and NS SSC12 2
SSC13
Table 3p esen s he expe imen al p og am de ined o e alua e he in luence o he
size o he agg ega es and he addi ion o silica mic o- and nanopa icles on he he mal
pe o mance o he de eloped mo a s. The pe cen age o silica mic o- and nanopa icles
we e he same and equal o 0.5% in weigh o binde o each one. All specimens we e
exposed o high empe a u es on one side up o 900
◦
C. Addi ionally, he expe imen al
p og am o es s ca ied ou on 12 SSC unde i e condi ions included h ee di e en i e
p o ec ion mo a s (CM, DCM, and DGMP). DGMV and o he s new ones will make pa
o ano he u u e expe imen al campaign, in which di e en agg ega es/addi i es will
be s udied.
2.3. P epa a ion o he Specimens
The manu ac u ing p ocess, shape, and dimensions o he SP and moulds we e de ined
o measu e he he mal g adien gene a ed be ween he inne su ace o he s eel pla e
exposed o high empe a u es and he exposed su ace o he i e p o ec ion mo a . Thus,
a sui able mould was designed and manu ac u ed o hese es s (Figu e 1).
Appl. Sci. 2021, 11, x FOR PEER REVIEW 6 o 22
2.3. P epa a ion o he Specimens
The manu ac u ing p ocess, shape, and dimensions o he SP and moulds we e de-
ined o measu e he he mal g adien gene a ed be ween he inne su ace o he s eel
pla e exposed o high empe a u es and he exposed su ace o he i e p o ec ion mo a .
Thus, a sui able mould was designed and manu ac u ed o hese es s (Figu e 1).
(a)
(b)
Figu e 1. Mould used in he manu ac u e o SP: (a) mould componen s; (b) mould assembly.
This mould assigns he desi ed geome ic shape o he specimen, was easy o
anspo and clean, was eusable o many expe imen al es s, and was easy o assemble
and disassemble when conc e ing and emo ing he specimen. Du ing he ab ica ion o
mo a s, a balance accu a e o 0.1 g , a g adua ed beake , Hoba N50 mixe wi h 5 L o
capaci y and a s ainless-s eel lab spa ula we e used. The p ocedu e adop ed in he ab i-
ca ion o mo a s was as ollows:
1. The aw ma e ials we e weighed and placed inside he mixe con aine .
2. Then, he mixe was pu in o ope a ion o 5 min a a slow speed (136 o a ions pe
minu e). A he same ime, he co esponding amoun o wa e was added, wi h a
cons an low a e o gua an ee he homogeneous addi ion o wa e in he whole mo -
a .
3. A e his p ocedu e, he mo a was manually kneaded wi h a spa ula o emo e
pa s o he mo a ha we e on he walls o he con aine and hus homogenize he
mix u e, hen e u ning he con aine o he mixe o ano he 2 min.
4. The mo a was placed inside he mould (Figu e 2).
In he p oduc ion o mo a s, he same p ocedu e was ollowed o ensu e ha he
di e en p ope ies o he mo a s we e only dependen on hei composi ion. To mini-
mize possible e ec s ha empe a u e and humidi y migh ha e on he p ope ies o each
mo a composi ion, all mix u es o each composi ion we e manu ac u ed on he same
day and placed in a oom wi h con olled en i onmen al condi ions. I is well known ha
he mois u e con en g ea ly in luences he i e beha io o mo a s a ele a ed empe a-
u es [39,40], in he same way as in he conc e es.
(a)
(b)
(c)
(d)
Figu e 1. Mould used in he manu ac u e o SP: (a) mould componen s; (b) mould assembly.
This mould assigns he desi ed geome ic shape o he specimen, was easy o anspo
and clean, was eusable o many expe imen al es s, and was easy o assemble and
disassemble when conc e ing and emo ing he specimen. Du ing he ab ica ion o
mo a s, a balance accu a e o 0.1 g, a g adua ed beake , Hoba N50 mixe wi h 5 L

Appl. Sci. 2022,12, 2093 6 o 20
o capaci y and a s ainless-s eel lab spa ula we e used. The p ocedu e adop ed in he
ab ica ion o mo a s was as ollows:
1. The aw ma e ials we e weighed and placed inside he mixe con aine .
2.
Then, he mixe was pu in o ope a ion o 5 min a a slow speed (136 o a ions
pe minu e). A he same ime, he co esponding amoun o wa e was added,
wi h a cons an low a e o gua an ee he homogeneous addi ion o wa e in he
whole mo a .
3.
A e his p ocedu e, he mo a was manually kneaded wi h a spa ula o emo e
pa s o he mo a ha we e on he walls o he con aine and hus homogenize he
mix u e, hen e u ning he con aine o he mixe o ano he 2 min.
4. The mo a was placed inside he mould (Figu e 2).
Appl. Sci. 2021, 11, x FOR PEER REVIEW 7 o 22
(a)
(b)
(c)
(d)
Figu e 2. Manu ac u e o specimens: (a) Hoba N50 mixe ; (b) esh mo a in he mixe con aine ;
(c) s eel pla e wi h he mocouples applied; (d) specimen in he p ocess o cu ing du ing he i s 48
h.
Abou 48 h a e cas ing he SP in he moulds desc ibed abo e, hey we e demoulded
and placed in he cu ing p ocess (Figu e 3a) o 28 days in he labo a o y en i onmen
wi h con olled empe a u e (25 °C) and a ela i e humidi y (RH) o 55%. The specimens
we e es ed wi h 6 mon hs o age.
(a)
(b)
Figu e 3. (a) Specimens in he p ocess o cu ing; (b) specimen schema ic ep esen a ion and e-
spec i e dimensions.
The specimens comp ised a S355 s eel pla e wi h a squa e sec ion o 250 mm o edge
and a hickness o 5 mm; and 10 mm hick i e p o ec ion mo a on one side o he s eel
pla e (Figu e 3b). The empe a u e measu emen in he SP was ca ied ou by placing 4
ype K he mocouples. The he mocouples we e placed a di e en dep hs ac oss he spec-
imen (Figu e 4).
(a)
(b)
Figu e 4. Schema ic iew o he mocouples. (a) A-A’-A’’ c oss-sec ion in he middle o he specimen;
(b) a angemen and designa ion o he mocouples.
Wi h his dis ibu ion o he mocouples, i was possible o de e mine he he mal
g adien be ween he su ace o he mo a exposed o high empe a u es (ESMHT— he -
mocouple 3) and he unexposed su ace (USMHT— he mocouple 2), as well as he em-
pe a u e on he inne su ace o he s eel pla e (ISSP— he mocouple 1) and i s ex e nal
Figu e 2.
Manu ac u e o specimens: (
a
) Hoba N50 mixe ; (
b
) esh mo a in he mixe con aine ;
(
c
) s eel pla e wi h he mocouples applied; (
d
) specimen in he p ocess o cu ing du ing he i s 48 h.
In he p oduc ion o mo a s, he same p ocedu e was ollowed o ensu e ha he
di e en p ope ies o he mo a s we e only dependen on hei composi ion. To minimize
possible e ec s ha empe a u e and humidi y migh ha e on he p ope ies o each mo a
composi ion, all mix u es o each composi ion we e manu ac u ed on he same day and
placed in a oom wi h con olled en i onmen al condi ions. I is well known ha he mois-
u e con en g ea ly in luences he i e beha io o mo a s a ele a ed
empe a u es [39,40],
in he same way as in he conc e es.
Abou 48 h a e cas ing he SP in he moulds desc ibed abo e, hey we e demoulded
and placed in he cu ing p ocess (Figu e 3a) o 28 days in he labo a o y en i onmen wi h
con olled empe a u e (25
◦
C) and a ela i e humidi y (RH) o 55%. The specimens we e
es ed wi h 6 mon hs o age.
Appl. Sci. 2021, 11, x FOR PEER REVIEW 7 o 22
Figu e 2. Manu ac u e o specimens: (a) Hoba N50 mixe ; (b) esh mo a in he mixe con aine ;
(c) s eel pla e wi h he mocouples applied; (d) specimen in he p ocess o cu ing du ing he i s 48
h.
Abou 48 h a e cas ing he SP in he moulds desc ibed abo e, hey we e demoulded
and placed in he cu ing p ocess (Figu e 3a) o 28 days in he labo a o y en i onmen
wi h con olled empe a u e (25 °C) and a ela i e humidi y (RH) o 55%. The specimens
we e es ed wi h 6 mon hs o age.
(a)
(b)
Figu e 3. (a) Specimens in he p ocess o cu ing; (b) specimen schema ic ep esen a ion and e-
spec i e dimensions.
The specimens comp ised a S355 s eel pla e wi h a squa e sec ion o 250 mm o edge
and a hickness o 5 mm; and 10 mm hick i e p o ec ion mo a on one side o he s eel
pla e (Figu e 3b). The empe a u e measu emen in he SP was ca ied ou by placing 4
ype K he mocouples. The he mocouples we e placed a di e en dep hs ac oss he spec-
imen (Figu e 4).
(a)
(b)
Figu e 4. Schema ic iew o he mocouples. (a) A-A’-A’’ c oss-sec ion in he middle o he specimen;
(b) a angemen and designa ion o he mocouples.
Wi h his dis ibu ion o he mocouples, i was possible o de e mine he he mal
g adien be ween he su ace o he mo a exposed o high empe a u es (ESMHT— he -
mocouple 3) and he unexposed su ace (USMHT— he mocouple 2), as well as he em-
pe a u e on he inne su ace o he s eel pla e (ISSP— he mocouple 1) and i s ex e nal
su ace (ESSP— he mocouple 4). In Figu e 5, i is possible o iden i y he he mocouples
on he specimen ollowing Figu e 4.
Figu e 3.
(
a
) Specimens in he p ocess o cu ing; (
b
) specimen schema ic ep esen a ion and espec i e
dimensions.
The specimens comp ised a S355 s eel pla e wi h a squa e sec ion o 250 mm o edge
and a hickness o 5 mm; and 10 mm hick i e p o ec ion mo a on one side o he s eel
pla e (Figu e 3b). The empe a u e measu emen in he SP was ca ied ou by placing
Appl. Sci. 2022,12, 2093 7 o 20
4 ype K he mocouples. The he mocouples we e placed a di e en dep hs ac oss he
specimen (Figu e 4).
Appl. Sci. 2021, 11, x FOR PEER REVIEW 7 o 22
Figu e 2. Manu ac u e o specimens: (a) Hoba N50 mixe ; (b) esh mo a in he mixe con aine ;
(c) s eel pla e wi h he mocouples applied; (d) specimen in he p ocess o cu ing du ing he i s 48
h.
Abou 48 h a e cas ing he SP in he moulds desc ibed abo e, hey we e demoulded
and placed in he cu ing p ocess (Figu e 3a) o 28 days in he labo a o y en i onmen
wi h con olled empe a u e (25 °C) and a ela i e humidi y (RH) o 55%. The specimens
we e es ed wi h 6 mon hs o age.
(a)
(b)
Figu e 3. (a) Specimens in he p ocess o cu ing; (b) specimen schema ic ep esen a ion and e-
spec i e dimensions.
The specimens comp ised a S355 s eel pla e wi h a squa e sec ion o 250 mm o edge
and a hickness o 5 mm; and 10 mm hick i e p o ec ion mo a on one side o he s eel
pla e (Figu e 3b). The empe a u e measu emen in he SP was ca ied ou by placing 4
ype K he mocouples. The he mocouples we e placed a di e en dep hs ac oss he spec-
imen (Figu e 4).
(a)
(b)
Figu e 4. Schema ic iew o he mocouples. (a) A-A’-A’’ c oss-sec ion in he middle o he specimen;
(b) a angemen and designa ion o he mocouples.
Wi h his dis ibu ion o he mocouples, i was possible o de e mine he he mal
g adien be ween he su ace o he mo a exposed o high empe a u es (ESMHT— he -
mocouple 3) and he unexposed su ace (USMHT— he mocouple 2), as well as he em-
pe a u e on he inne su ace o he s eel pla e (ISSP— he mocouple 1) and i s ex e nal
su ace (ESSP— he mocouple 4). In Figu e 5, i is possible o iden i y he he mocouples
on he specimen ollowing Figu e 4.
Figu e 4.
Schema ic iew o he mocouples. (
a
) A-A’-A” c oss-sec ion in he middle o he specimen;
(b) a angemen and designa ion o he mocouples.
Wi h his dis ibu ion o he mocouples, i was possible o de e mine he he mal
g adien be ween he su ace o he mo a exposed o high empe a u es (ESMHT—
he mocouple 3) and he unexposed su ace (USMHT— he mocouple 2), as well as he
empe a u e on he inne su ace o he s eel pla e (ISSP— he mocouple 1) and i s ex e nal
su ace (ESSP— he mocouple 4). In Figu e 5, i is possible o iden i y he he mocouples on
he specimen ollowing Figu e 4.
Appl. Sci. 2021, 11, x FOR PEER REVIEW 8 o 22
Figu e 5. Iden i ica ion o he mocouples, 1–4, on he specimen ollowing Figu e 4.
Conce ning he SSCs es s, specimens we e de ined by a hollow squa e sec ion 150 ×
150 × 8 mm, wi h a heigh o 1250 mm, and he s eel g ade was S355. A he column ends,
i was cen e ed and welded a s eel pla e (sec ion 300 × 300 × 20 mm), as shown in Figu e
8. To e alua e he empe a u e e olu ion on he ex e nal su aces o he s eel columns
du ing he es , 12 ype K he mocouples we e welded, equidis an om each o he on all
he specimen’s su aces, applied in 3 g oups o 4 he mocouples a di e en heigh s. These
e mocouples we e welded in he middle o he su aces o he s eel ubula columns. To
gua an ee a cons an and uni o m mo a hickness o 20 mm along he s eel columns, a
modula o mwo k was de eloped wi h he abili y o assign he desi ed geome ic shape-
wi h easy assembly and disassembly while conc e ing he specimen. Figu e 6 depic s he
loca ion o he h ee g oups o he mocouples and he di e en conc e ing s eps o he
s eel columns. The specimens we e es ed a e cu ing o 6 mon hs.
Figu e 5. Iden i ica ion o he mocouples, 1–4, on he specimen ollowing Figu e 4.
Conce ning he SSCs es s, specimens we e de ined by a hollow squa e sec ion
150 ×150 ×8 mm,
wi h a heigh o 1250 mm, and he s eel g ade was S355. A he column
ends, i was cen e ed and welded a s eel pla e (sec ion 300
×
300
×
20 mm), as shown
in Figu e 8. To e alua e he empe a u e e olu ion on he ex e nal su aces o he s eel
columns du ing he es , 12 ype K he mocouples we e welded, equidis an om each
o he on all he specimen’s su aces, applied in 3 g oups o 4 he mocouples a di e en
heigh s. These e mocouples we e welded in he middle o he su aces o he s eel ubula
columns. To gua an ee a cons an and uni o m mo a hickness o 20 mm along he s eel
columns, a modula o mwo k was de eloped wi h he abili y o assign he desi ed geo-
Appl. Sci. 2022,12, 2093 8 o 20
me ic shapewi h easy assembly and disassembly while conc e ing he specimen. Figu e 6
depic s he loca ion o he h ee g oups o he mocouples and he di e en conc e ing s eps
o he s eel columns. The specimens we e es ed a e cu ing o 6 mon hs.
Appl. Sci. 2021, 11, x FOR PEER REVIEW 9 o 22
(a)
(b)
(c)
(d)
Figu e 6. Dis ibu ion o he mocouples (a) and ab ica ion o specimens, p econc e ing (b), con-
c e ing on he sho s eel columns (c), and conc e e specimen wi hou o mwo k (d).
2.4. Expe imen al Tes ing Sys em and P ocedu e
The expe imen al es ing sys em (Figu e 7) used in he mal analysis o s eel pla es
consis ed o a cylind ical o en wi h in e nal dimensions 400 mm in heigh and 250 mm in
diame e , capable o eaching a maximum empe a u e o 1200 °C (a) and he espec i e
o en con olle (b). A Da alogge TDS-530 was used as a da a acquisi ion sys em (c) o
eco d he empe a u e eadings. Rega ding he es p ocedu e, a e sealing all he exis -
ing unions and holes o he o en wi h ock wool, a 8 cm hick ock wool blanke wi h a
ci cula opening o 210 mm in diame e was also placed on he op o he o en (e), which
allows he passage o hea om he in e io o he o en o he specimen. Subsequen ly,
he specimen (d) was placed on he op o he o en, i.e., on he ock wool blanke and
cen ed wi h he ba ycen ic axis o he o en.
Figu e 7. Expe imen al se up: (a) cylind ical o en(b) o en con olle (c) da a acquisi ion sys em(d)
specimen(e) ock wool.
In all es s, he specimens we e placed in a sui able posi ion o ensu e pe ec accom-
moda ion wi h he ock wool and hus a oid hea losses be ween he specimen and he
o en. The specimen was hea ed a a hea ing a e o 15 °C/minu e un il eaching he desi ed
empe a u e le el (900 °C). Tempe a u es inside he specimen and he o en we e
Figu e 6.
Dis ibu ion o he mocouples (
a
) and ab ica ion o specimens, p econc e ing (
b
), conc e -
ing on he sho s eel columns (c), and conc e e specimen wi hou o mwo k (d).
2.4. Expe imen al Tes ing Sys em and P ocedu e
The expe imen al es ing sys em (Figu e 7) used in he mal analysis o s eel pla es
consis ed o a cylind ical o en wi h in e nal dimensions 400 mm in heigh and 250 mm in
diame e , capable o eaching a maximum empe a u e o 1200
◦
C (a) and he espec i e
o en con olle (b). A Da alogge TDS-530 was used as a da a acquisi ion sys em (c) o
eco d he empe a u e eadings. Rega ding he es p ocedu e, a e sealing all he exis ing
unions and holes o he o en wi h ock wool, a 8 cm hick ock wool blanke wi h a ci cula
opening o 210 mm in diame e was also placed on he op o he o en (e), which allows he
passage o hea om he in e io o he o en o he specimen. Subsequen ly, he specimen
(d) was placed on he op o he o en, i.e., on he ock wool blanke and cen ed wi h he
ba ycen ic axis o he o en.
Appl. Sci. 2021, 11, x FOR PEER REVIEW 9 o 22
(a)
(b)
(c)
(d)
Figu e 6. Dis ibu ion o he mocouples (a) and ab ica ion o specimens, p econc e ing (b), con-
c e ing on he sho s eel columns (c), and conc e e specimen wi hou o mwo k (d).
2.4. Expe imen al Tes ing Sys em and P ocedu e
The expe imen al es ing sys em (Figu e 7) used in he mal analysis o s eel pla es
consis ed o a cylind ical o en wi h in e nal dimensions 400 mm in heigh and 250 mm in
diame e , capable o eaching a maximum empe a u e o 1200 °C (a) and he espec i e
o en con olle (b). A Da alogge TDS-530 was used as a da a acquisi ion sys em (c) o
eco d he empe a u e eadings. Rega ding he es p ocedu e, a e sealing all he exis -
ing unions and holes o he o en wi h ock wool, a 8 cm hick ock wool blanke wi h a
ci cula opening o 210 mm in diame e was also placed on he op o he o en (e), which
allows he passage o hea om he in e io o he o en o he specimen. Subsequen ly,
he specimen (d) was placed on he op o he o en, i.e., on he ock wool blanke and
cen ed wi h he ba ycen ic axis o he o en.
Figu e 7. Expe imen al se up: (a) cylind ical o en(b) o en con olle (c) da a acquisi ion sys em(d)
specimen(e) ock wool.
In all es s, he specimens we e placed in a sui able posi ion o ensu e pe ec accom-
moda ion wi h he ock wool and hus a oid hea losses be ween he specimen and he
o en. The specimen was hea ed a a hea ing a e o 15 °C/minu e un il eaching he desi ed
empe a u e le el (900 °C). Tempe a u es inside he specimen and he o en we e
Figu e 7.
Expe imen al se up: (
a
) cylind ical o en (
b
) o en con olle (
c
) da a acquisi ion sys em
(d) specimen (e) ock wool.
Appl. Sci. 2022,12, 2093 9 o 20
In all es s, he specimens we e placed in a sui able posi ion o ensu e pe ec accom-
moda ion wi h he ock wool and hus a oid hea losses be ween he specimen and he
o en. The specimen was hea ed a a hea ing a e o 15
◦
C/minu e un il eaching he desi ed
empe a u e le el (900
◦
C). Tempe a u es inside he specimen and he o en we e measu ed
e e y 5 s. When he a ge empe a u e in he specimen was eached, i was main ained
uni o m du ing 3 h and a e , he es was gi en as concluded.
The expe imen al layou o he sho s eel columns (SSC) unde i e condi ions
(Figu e 8)
consis ed essen ially o a eac ion s eel ame (A) o apply he se iceabili y
load on he specimen, a suppo s eel ame (B), a hyd aulic jack (C), and an elec ic
u nace (H).
Appl. Sci. 2021, 11, x FOR PEER REVIEW 10 o 22
measu ed e e y 5 s. When he a ge empe a u e in he specimen was eached, i was
main ained uni o m du ing 3 h and a e , he es was gi en as concluded.
The expe imen al layou o he sho s eel columns (SSC) unde i e condi ions (Fig-
u e 8) consis ed essen ially o a eac ion s eel ame (A) o apply he se iceabili y load on
he specimen, a suppo s eel ame (B), a hyd aulic jack (C), and an elec ic u nace (H).
Figu e 8. Expe imen al sys em used in he labo a o y o es SSCS. The le e s in his igu e a e de-
ined in he ollowing ex .
This s eel ame was de ined by HEB 500 columns and a HEB 600 beam (A), wi h a
s i ness capable o minimizing possible displacemen s o his s eel s uc u e du ing he
es s. Addi ionally, a suppo 3D s eel ame consis ing o wo ames (B) wi h HEB 300
columns and HEB 400 beams accommoda e he es ing specimen o simila ac ual bound-
a y condi ions. Rega ding he es equipmen , a 3 MN hyd aulic jack (C) and i s con olle
(J), a 3 MN load cell (D), and a 1 MN load cell (E) we e used o measu ing he comp ession
o ces. Ten linea a iable displacemen ansduce s we e used o displacemen s meas-
u emen s (F), a Da alogge (G) o da a acquisi ion, and an elec ic u nace (H) o hea up
he s eel columns (I).
A hyd aulic jack con olled by a se o-con olled cen al was used, and a p eload o
50% o he design alue o he loadbea ing capaci y o he columns a ambien empe a-
u e (ULS) was applied (727.8 kN) o simula e a se ice load on he specimen. A e s abi-
lising his loading in he specimen, he u nace was swi ched on and he specimen hea ed
acco ding o he empe a u e e olu ion es ablished by he ISO 834 s anda d i e cu e [41].
Figu e 8.
Expe imen al sys em used in he labo a o y o es SSCS. The le e s in his igu e a e
de ined in he ollowing ex .
This s eel ame was de ined by HEB 500 columns and a HEB 600 beam (A), wi h
a s i ness capable o minimizing possible displacemen s o his s eel s uc u e du ing
he es s. Addi ionally, a suppo 3D s eel ame consis ing o wo ames (B) wi h HEB
300 columns and HEB 400 beams accommoda e he es ing specimen o simila ac ual
bounda y condi ions. Rega ding he es equipmen , a 3 MN hyd aulic jack (C) and i s
con olle (J), a 3 MN load cell (D), and a 1 MN load cell (E) we e used o measu ing he
comp ession o ces. Ten linea a iable displacemen ansduce s we e used o displace-
men s measu emen s (F), a Da alogge (G) o da a acquisi ion, and an elec ic u nace (H)
o hea up he s eel columns (I).
Appl. Sci. 2022,12, 2093 16 o 20
Table 8. A e age empe a u e alue ob ained on he specimens o SSC.
Di e en Types o
Tes ed Columns
Specimens
Designa ion
A e age Tempe a u e
o Specimens (◦C) C i ical
Tempe a u e (◦C)
A e age
Failu e Time Fi e
Resis ance
Ra ing
15 30 60 90
(Minu es) (Failu e Time) (Minu es)
Columns wi hou
passi e i e p o ec ion SSC1 525 - - - 560 ◦C (17 min) 17 R15
SSC2 572 - - - 617 ◦C (17 min)
Columns coa ed
wi h CM
SSC3 78 111 351 - 560 ◦C (85 min) 81 R60
SSC4 77 108 360 - 531 ◦C (77 min)
Column coa ed
wi h DCM
Wi hou MS
and NS
SSC5 96 220 465 - 566 ◦C (82 min) 83 R60
SSC6 103 242 481 - 585 ◦C (84 min)
Wi h
MS and NS
SSC11 96 193 447 - 582 ◦C (88 min) 90 R90
SSC14 92 186 425 557 559 ◦C (91 min)
Column coa ed
wi h DGMP
Wi hou MS
and NS
SSC7 79 115 341 535 576 ◦C (98 min) 97 R90
SSC8 75 119 342 545 572 ◦C (95 min)
Wi h
MS and NS
SSC12 76 116 328 516 566 ◦C (102 min) 100 R90
SSC13 76 114 328 525 564 ◦C (98 min)
Appl. Sci. 2021, 11, x FOR PEER REVIEW 17 o 22
Figu e 13. E olu ion o empe a u e in he specimens o SSC as a unc ion o ime.
Table 8 shows he a e age empe a u e alues acqui ed in he specimens a e 15, 30,
60, and 90 min and he a e age empe a u e alues o he ailu e ins an s o each speci-
men. The c i ical design empe a u e calcula ed acco ding o EN 1993-1-2: 2005 [41] o
his sho s eel column was 586.7°C.
In Figu e 12, he es ed SSC2 ailed a 17 min, SSC4 a 77 min, SSC6 a 84 min, SSC8
a 95 min, SSC12 a 102 min, and SSC14 a 91 min, co esponding o he empe a u e o
617, 531, 585, 572, 566, and 559°C, espec i ely (see also Table 8). In Figu e 13 and Table 8,
i can be seen ha he comme cial mo a has a mo e e ec i e he mal p o ec ion o lowe
empe a u es ( he highes delay in he empe a u e ise a he beginning o he es ). How-
e e , o empe a u es highe han 400°C, i s he mal capaci y ends o dec ease due o he
deg ada ion o he mo a ( he highes empe a u e ise a e a he ending o he es ).
Figu e 14 depic s he specimen be o e and a e being es ed. Rega ding he ins abil-
i y modes o he s eel columns, local ins abili y was obse ed despi e he column being a
class 1 c oss-sec ion unde i e condi ions.
Figu e 14. Pho os o he specimens o SSC be o e and a e es ed, as an example.
0
200
400
600
800
1000
1200
010 20 30 40 50 60 70 80 90 100 110
Tempe a u e (°C)
Time (minu es)
ISO 834
Fu nace
Tempe a u e
TSSC1,SSC2
TSSC3,SSC4
TSSC5,SSC6
TSSC7,SSC8
TSSC12,SSC13
TSSC11,SSC14
Figu e 14. Pho os o he specimens o SSC be o e and a e es ed, as an example.
The esul s om Table 8clea ly show ha he applica ion o mo a s wo ks as a good
he mal ba ie o i e, since columns wi hou passi e i e p o ec ion ailed a e 17 min o
es ing, whe eas he p o ec ed columns ailed on a e age, beyond 81 min. Fu he mo e, he
esul s also show ha he he mal p o ec ion o mo a s de eloped in he labo a o y was
mo e e icien han ha p o ided by he comme cial mo a s. Finally, i appea s ha he
in oduc ion o he NS and MS sligh ly imp o ed he he mal pe o mance o he mo a s
de eloped in he labo a o y.
Table 8shows ha he specimen wi hou passi e i e p o ec ion p esen ed a i e
esis ance a ing (FRR) o 15 min (R15), and he p o ec ed specimens wi h he CM allowed
a FRR o R60. Conce ning he he mal pe o mance o he mo a s de eloped in he
labo a o y, i was ound ha he specimens p o ec ed wi h he DCM had a FRR o R60.
When NS and MS we e added o i s composi ion, a FRR inc eased o R90. The specimens
p o ec ed wi h he DGMP, wi h and wi hou NS and MS, p esen ed a FRR o R90.
The indings esul s ob ained om he sho s eel columns p o ec ed wi h he di e en
mo a s ypes we e in ag eemen wi h he ones ob ained in he es s ca ied ou on he
p o ec ed s eel pla es, which makes hese explo a o y es s use ul o p elimina y selec ion
o p omising i e p o ec ion ma e ials.

Appl. Sci. 2022,12, 2093 17 o 20
4. Conclusions
The objec i e o his wo k was o de elop gypsum o cemen -based mo a s o passi e
i e p o ec ion and o e alua e he in luence o agg ega e size and he addi ion o silica
mic o- and nanopa icles on i s he mal pe o mance. The he mal pe o mance o hese
mo a s in sho s eel columns unde a comp ession se ice load and subjec ed o high
empe a u es was assessed. The ollowing conclusions can be d awn:
•
The u nace, he dimensions o he specimens, and he es p ocedu e adop ed in he
es s a high empe a u es allowed an adequa e he mal exposu e o he specimens. I
allowed he e alua ion o he he mal pe o mance o he a ious mo a s es ed.
•
Some mo a s de eloped in he labo a o y (DCM, DGMP, and DGMV) ha e be e
he mal pe o mance when compa ed wi h he bes comme cial solu ion es ed (CM).
Fu he mo e, in his se o mo a s wi hou nano- and mic opa icles o silica, he mo a s
wi h e miculi e in hei cons i u ion we e hose wi h he bes he mal pe o mance.
•
Mos mo a s wi h aw ma e ial milled h ough he Los Angeles me hod had be e
he mal pe o mance han mo a s de eloped wi h aw ma e ial p ocessed h ough
he Indus ial Mill me hod. Howe e , i nano- and mic opa icles o silica a e added
in hei composi ion, he mo a s de eloped wi h aw ma e ial ob ained h ough he
Indus ial Mill me hod may ha e a sligh ly supe io he mal pe o mance.
•
The addi ion o nano- and mic opa icles o silica imp o es he insula ing capaci y o
he mo a s.
•
O e all, he esul s demons a e ha he educ ion in g ain size o he aw ma e-
ials used (pe li e and e miculi e) did no bene i he he mal pe o mance o he
es ed composi ions.
•
Rega ding he c acking o he mo a s, i was concluded ha pe li e (DGMP) con-
ibu es o i s low alue. I was also concluded ha , in gene al e ms, he addi ion o
NS and MS ends o inc ease he c acking deg ee o he de eloped composi ions.
•
The composi ions ha use gypsum as a binde (DGMP and DGMV) had he bes he -
mal insula ion capaci y. Unde he es ed condi ions, i was ound ha 10 mm o mo a
coa ing was su icien o o m an e icien he mal ba ie , educing he ISSP empe a-
u e by app oxima ely 70% o he empe a u e eco ded inside he o en (900 ◦C).
•
The he mal p o ec ion le el o columns wi h he mo a de eloped in he labo a o y
wi h he bes o e all he mal pe o mance (DGMP wi h nano- and mic opa icles o
silica) was 19% mo e e icien han he comme cial solu ion and inc eases by 5.9 imes
he i e esis ance o an unp o ec ed sho s eel column. These esul s demons a ed he
ac ual impac ha he applica ion o such mo a s can ha e as passi e i e p o ec ion
o s eels s uc u es.
Bea ing in mind he expe imen al indings ob ained in his esea ch s udy, u he
expe imen al es s on sho s eel columns wi h he de eloped mo a s and new ones by
using di e en addi i es as well as wi h di e en loading condi ions will be ca ied ou in
he nea u u e.
Au ho Con ibu ions:
Concep ualiza ion, H.C. and A.S. (Aldina San iago); me hodology, H.C.;
so wa e, A.S. (Aldina San iago); alida ion, L.L., L.D. and A.S. (Ashkan Shahbazian); o mal analysis,
H.C.; in es iga ion, H.C.; esou ces, A.S. (Aldina San iago); da a cu a ion, A.S. (Aldina San iago);
w i ing—o iginal d a p epa a ion, H.C.; w i ing— e iew and edi ing, L.L.; isualiza ion, H.C.;
supe ision, H.C.; p ojec adminis a ion, A.S. (Aldina San iago); unding acquisi ion, A.S. (Aldina
San iago). All au ho s ha e ead and ag eed o he published e sion o he manusc ip .
Funding:
This esea ch was unded by he Po uguese Founda ion o Science and Technology (FCT),
g an numbe PTDC/ECI-EGC/31850/2017.
Ins i u ional Re iew Boa d S a emen : No applicable.
In o med Consen S a emen : No applicable.
Appl. Sci. 2022,12, 2093 18 o 20
Acknowledgmen s:
The au ho s g a e ully acknowledge he Po uguese Founda ion o Science and
Technology (FCT) o i s suppo unde he amewo k o esea ch p ojec PTDC/ECI-EGC/31850/2017
(NANOFIRE—The mal and Mechanical beha iou o Nano Cemen s and hei applica ion in s eel
cons uc ion as i e p o ec ion) and also o he Uni e si y o Coimb a (UC) o hei suppo unde
he Scien i ic Employmen S imulus P og amme gi en o he i s au ho , as well as o he Eu opean
Regional De elopmen Fund, he Eu opean Social Fund, and Eu opean S uc u al and In es men
Funds. This wo k was also inanced by FEDER unds h ough he Compe i i i y Fac o s Ope a ional
P og amme—COMPETE and by na ional unds h ough FCT wi hin he scope o he p ojec POCI-
01-0145-FEDER-007633 and h ough he Regional Ope a ional P og amme CENTRO2020 wi hin he
scope o he p ojec CENTRO-01-0145-FEDER-000006.
Con lic s o In e es : The au ho s decla e no con lic o in e es .
Abb e ia ions
CM Comme cial passi e p o ec ion solu ion used as a e e ence mo a
CPPS Comme cial passi e p o ec ion solu ion
DCM De eloped cemen i ious mo a
DGMP De eloped gypsum mo a wi h pe li e
DGMV De eloped gypsum mo a wi h e miculi e
DRCM De eloped e ac o y cemen i ious mo a
EC Expanded clay
EP Expanded pe li e
ERC Ele oland e ac o y cemen
ESMHT Exposed su ace o he mo a o high empe a u es
ESSP Ex e nal su ace o he s eel pla e o he es specimen
EV Expanded e miculi e
GP Gypsum powde
IGN Comme cial passi e p o ec ion solu ion 1
IM Indus ial mill me hod
IRC Isidac 40 e ac o y cemen
ISSP Inne su ace o he s eel pla e o he es specimen
LA Los Angeles me hod
MS Mic opa icles o silica
NS Nanopa icles o silica
PC Po land cemen CEM II/B-L 32.5
PP Polyp opylene ibe s
PP/B Polyp opylene ibe s cemen a io in weigh %
RC Re ac o y cemen
RH Rela i e humidi y
SD S anda d de ia ion
SP S eel pla e
SS Silica sand
SSC Sho s eel columns
T Tempe a u e
Time
TH The mocouple
TRC Topeca M40 e ac o y cemen
USMHT Unexposed su ace o he mo a o high empe a u es
VER Comme cial passi e p o ec ion solu ion 2
W Wa e
W/B Wa e binde (cemen o gypsum) a io in weigh %
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