Evaluation of the physical and mechanical behaviour of rammed earth by incorporation of recycled glass

b o l e í n d e l a s o c i e d a d e s p a ñ o l a d e c e á m i c a y i d i o 6 4 (2 0 2 5) 100442 www.else ie .es/bsec E alua ion o he physical and mechanical beha iou o ammed ea h by inco po a ion o ecycled glass Jacin o Cani ella, Juan Jesús Ma in-del-Rioa, Ma io Solísb, José Daniel Rod íguez-Ma iscalb, Vicen e Flo es-Alésa,∗, F ancisco Pon igac aDepa men o A chi ec u al Cons uc ion II, Uni e sidad de Se illa, A . Reina Me cedes 4, 41012 Se illa, Spain bDepa men o Mechanics o Con inuous Media and Theo y o S uc u es, Uni e sidad de Se illa, Camino Descub imien os, s/n – Isla Ca uja, 41092 Se illa, Spain cDepa men o Applied Physics II, Uni e sidad de Se illa, A . Reina Me cedes 4, 41012 Se illa, Spain a i c l e i n o A icle his o y: Recei ed 5 Ma ch 2025 Accep ed 2 May 2025 A ailable online 2 June 2025 Keywo ds: Rammed ea h Comp essi e s eng h Non-des uc i e es ing Agg ega e subs i u ion C ushed glass a b s a c Compac ed soil walls p o ide en i onmen al benefi s due o hei low impac and embodied ene gy. Al hough hei mechanical s eng h is lowe han o he ma e ials, hey mee sa e y equi emen s. Cu en ends p omo e ci cula economy solu ions, such as was e euse. This s udy assesses ecycled glass in lime- and cemen -s abilized ammed ea h as a eplacemen o na u al sand o enhance was e managemen and soil p ope ies. Ul asonic inspec ion confi ms inc eased comp essi e s eng h and densi y, especially in cemen -s abilized mix- u es. S a is ical analysis e eals a di ec co ela ion be ween c ushed glass con en and imp o ed p ope ies. The op imal eplacemen a e is 75% o lime and 100% o cemen . The supe io pe o mance in cemen -s abilized samples is due o a pozzolanic eac ion absen in lime mix u es. Bo h binde s show significan educ ions in he mal conduc i i y, imp o ing ene gy e ficiency wi hou comp omising s uc u al in eg i y. Ul asound p o es eliable o p edic ing comp essi e s eng h and s i ness, suppo ing he iabili y o his app oach. The inco po a ion o ecycled glass in compac ed soil o e s a sus ainable con- s uc ion al e na i e, balancing en i onmen al benefi s wi h enhanced mechanical and he mal pe o mance. © 2025 The Au ho s. Published by Else ie Espa˜ na, S.L.U. on behal o SECV. This is an open access a icle unde he CC BY-NC-ND license (h p://c ea i ecommons.o g/licenses/ by-nc-nd/4.0/). ∗Co esponding au ho . E-mail add ess: fl[email p o ec ed] (V. Flo es-Alés). h ps://doi.o g/10.1016/j.bsec .2025.100442 0366-3175/© 2025 The Au ho s. Published by Else ie Espa˜ na, S.L.U. on behal o SECV. This is an open access a icle unde he CC BY-NC-ND license (h p://c ea i ecommons.o g/licenses/by-nc-nd/4.0/). 2 b o l e í n d e l a s o c i e d a d e s p a ñ o l a d e c e á m i c a y i d i o 6 4 (2 0 2 5) 100442 E aluación del compo amien o ísico y mecánico de la ie a compac ada con inco po ación de id io eciclado Palab as cla e: Tie a apisonada Resis encia a la comp esión Ensayos no des uc i os Sus i ución de á idos Vid io i u ado e s u m e n Los mu os de suelo compac ado o ecen beneficios ambien ales po su bajo impac o y ene gía inco po ada. Aunque su esis encia mecánica es meno que o os ma e iales, cumplen con los equisi os de segu idad. Las endencias ac uales omen an soluciones alin- eadas con la economía ci cula , como la eu ilización de esiduos. Es e es udio e alúa el uso de id io eciclado en ie a compac ada es abilizada con cal y cemen o como sus i u o de la a ena na u al pa a mejo a la ges ión de esiduos y las p opiedades del suelo. La inspección ul asónica confi ma un aumen o en la esis encia a comp esión y la densidad, especial- men e en mezclas es abilizadas con cemen o. El análisis es adís ico e ela una co elación di ec a en e el con enido de id io i u ado y la mejo a de p opiedades. La asa óp ima de sus i ución es 75% pa a cal y 100% pa a cemen o. El mejo desempe˜ no en mezclas con cemen o se debe a una eacción puzolánica ausen e en las de cal. Ambos aglome an es educen significa i amen e la conduc i idad é mica, mejo ando la eficiencia ene gé ica sin a ec a la in eg idad es uc u al. El ul asonido esul a fiable pa a p edeci la esis encia y igidez, alidando es a es a egia. La in eg ación de id io eciclado en suelo compac ado es una al e na i a sos enible, combinando beneficios ambien ales con mejo as mecánicas y é micas. © 2025 Los Au o es. Publicado po Else ie Espa˜ na, S.L.U. en nomb e de SECV. Es e es un a ´ ıculo Open Access bajo la CC BY-NC-ND licencia (h p://c ea i ecommons.o g/licencias/ by-nc-nd/4.0/). In oduc ion The cons uc ion wi h soil may seem a simple echnology [1], bu hese echniques ha e been de eloped and imp o ed o p o ide be e p ocess pe o mance. I is also a cleane , heal h- ie and less ene gy-consuming p ocess han o he s, such as b ick making, in which a fi ing phase is necessa y. The ech- niques di e by he applica ion and handling o he ma e ial. Two la ge g oups can be dis inguished, one o hem in which he cons uc ion wi h ea h suppo s a load and he o he whe e he soil is only a fille . In he fi s g oup a e echniques such as ammed ea h, adobe, cob and comp essed ea h block (CEB). The CEB is simila o adobe, bu in his case, he soil is subjec ed o high s a ic p essu e, which inc eases he com- p essi e s eng h o he ma e ial. They a e building blocks made om a mix u e o soil, sand and clay, and may also con- ain lime o cemen as a s abilize . Since hey a e buil -on-si e he echnical equi emen s a e low in compa ison o CEBs. Mo eo e , ammed ea h walls a e made by dynamic p essu e wi h low ene gy pe impac , hence he o mwo k does no need o wi hs and ex eme o ces. In bo h cases hey sha e simila physical–mechanical p ope ies. The ea hen walls ha e an ad an age p o iding a high he mal insula ion capaci y [2,3], hey egula e he en i on- men o he house in a na u al way. The CEB and ammed ea h a e no fi ed, so hey p ese e he o iginal p ope ies o he ea h walls, egula e humidi y and accumula e hea . This compac ing echnique can also be ca ied ou in si u, whene e he cons uc ion si e allows i , by means o a com- p ession machine. To p oduce he CEB and ammed ea h, only abou 1% o he ene gy equi ed o make a con en ional b ick is needed, wi h minimal CO2emissions. Ano he ad an age is ha comp essed ea h walls main ain a cons an ela i e humidi y o a ound 50%, equi ing less ene gy o hea hem han in a adi ional building [4]. The inco po a ion o agg ega es om was e is an al e na- i e ha has been in es iga ed wi h he aim o imp o ing he p ope ies o he final p oduc and inc easing i s sus ainabili y [5–7]. The possibili y o inco po a ing c ushed glass is a sim- ple and clean op ion ha , acco ding o p e ious esea ch, will imp o e he he mal insula ion capaci y [8]. Was e glass has adi ionally been used in compac ed soil, as a subs i u e o sand in conc e e [9] and geo echnical p oduc s, mos ly as a fille ma e ial, as a plas ici y modifie [10], al hough in hose cases whe e an alkaline ac i a o is inco po a ed, such was e can also de elop chemical s abilisa ion capaci y depending on i s pa icle size [11–13]. O he au ho s ha e epo ed educ- ions in he mal conduc i i y o a ound 38% o ligh weigh conc e es wi h he inco po a ion o 45% glass [14]. The mean alue o he he mal conduc i i y o ammed ea h wall can be defined in he ange 0.5–1.7 W/mK [15], which indica es a ela i ely poo he mal pe o mance o ammed ea h walls. In ela ion o he mal conduc i i y, he he mal conduc i i y coe ficien o glass om domes ic sou ces is es i- ma ed a an a e age alue o 0.8 W/mK, al hough his can a y depending on he cha ac e is ics and o igin o he ma e ial [8], so i s inco po a ion in o ammed ea h elemen s con ibu es o he he mal conduc i i y o hese being a he lowe end o he ange [16,17]. The inco po a ion o glass in comp essed ea h walls has also been s udied in o de o imp o e pa icle s abilisa ion and o ob ain an inc ease in mechanical capabili ies [18]. Fo example, powde ed glass has been used by an alkaline ac i- a ion p ocess [6,11] o achie e subs an ial imp o emen s in b o l e í n d e l a s o c i e d a d e s p a ñ o l a d e c e á m i c a y i d i o 6 4 (2 0 2 5) 100442 3 Table 1 – Chemical analysis o he AFN clay, acco ding o manu ac u e da a-shee and A e be g limi s. Chemical analysis (%) Plas ici y SiO2Al2O3Fe2O3TiO2CaO MgO Na2O K2O MnO L.O.I. L.L. P.I. 57.59 17.63 6.38 0.39 3.40 2.14 0.18 3.16 0.08 8.75 34 15 L.O.I.: los on igni ion; L.L.: liquid limi ; P.L.: plas ici y index. Table 2 – Mine alogical composi ion o he AFN clay. Mine als % by weigh O hoclase (K- eldspa ) 5 Qua z 39 Albi e (Na- eldspa ) >1 Hema i e 2 Calci e 4 Musco i e 37 Chlo i e 13 comp essi e s eng h and du abili y. Alkaline ac i a ion has also been used o imp o e he consolida ion o ea h mo a s o es o a ion [19] wi h alid esul s o low alkaline con- cen a ions. Alkaline ac i a ion has also been conside ed o ammed ea h [20] and o CEB [21] bu wi hou including he inco po a ion o ecycled o powde ed glass [22]. In bo h cases, i is highligh ed ha his ype o chemical eac ion p o ides a be e bonding ma ix and he e o e a highe mechanical pe o mance. Since he e is sca ce esea ch on he inco po a ion o ecycled glass in cons uc ion echniques using compac ed ea h, he aim o his esea ch is he analysis o he physical–mechanical pe o mance o inco po a ing c ushed glass in s abilised ammed ea h. Physical and mechanical p ope ies will be e alua ed, depending on di e en pe cen - ages o subs i u ion o he fine ac ions o na u al agg ega e. The esea ch aims o de e mine whe he he e a e signifi- can imp o emen s in he a o emen ioned p ope ies and, i so, wha pe cen age o glass subs i u ion would be op imal, assessing i s ad an ages and disad an ages. Ma e ial and me hods The soil used in his s udy was a ificial manu ac u ed om sepa a ed ac ions so ha a homogenei y is achie ed be ween di e en ba ches. The soil is composed by a mix o g a el, coa se and fine sands and clay. The lime was pu chased om a local company while he clay came om a specialised man- u ac u e (Sio-2®), who supplied i in powde o m so ha i could be easily mixed d y wi h all he agg ega es. The chemi- cal analyses o he clay AFN om Sio-2 a e depic ed in Table 1. The mine alogical composi ion o he clay is shown in Fig. 1 and i s quan ifica ion in Table 2. C ushed glass was s udied as subs i u e o sand, main ain- ing he es ablished pe cen age o g a el. The c ushed glass was p o ided by Ra sa S.A., a glass ecycling company. The glass was c ushed, by a mechanical g inding machine. Agg e- ga e sizes la ge han 4 mm we e emo ed. A soil ype was designed ha was composed o 15% g a el, 50% coa se sand, 20% fine sand and 15% clay, which we e d y- mixed p io o he p epa a ion o he specimens. Acco ding o UNE-EN 9333-1 sie ing me hod, hese p opo ions comply wi h a pa icle size dis ibu ion o good compac ness, since as can be seen in Fig. 2A, he cu e co esponding o he soil has no discon inui ies and emains close o i s co espond- ing Fulle and i s fineness modulus (4.29) is simila o ha o i s Fulle (4.79). The c ushed glass ha will eplace he sand ac ions is ep esen ed in Fig. 2B, whe e he simila i y o bo h agg ega es is obse ed. The expe imen al design conside ed he pa ial and o al subs i u ion wi h c ushed glass o he sand ac ions. As he in en ion is o analyse he beha iou o glass as a subs i u e o agg ega e, 50, 75 and 100 pe cen ages we e sough in o de o obse e possible changes in beha iou . In addi ion, a e - e ence dosage wi hou glass was conside ed. This glass is a by-p oduc om lamina ed pans o glass and was chemically cha ac e ized by means o X- ay fluo escence (XRF) in a Pana- ly ical X- ay fluo escence spec ome e (AXIOS) wi h Rh ube o elemen al solid sample analysis (Table 3). The analyses we e ca ied ou on pea l p ocessed a 1200◦C using li hium me abo a e and li hium e abo a e as fluxes in a a io o 34/66. The flux/sample a io used was 9/1. This soil was s abilized by Po land cemen (C) and hyd aulic lime HL5 (L), bo h in a pe cen age o 5% by mass o d ied soil, being wi hin he op imal ange s a ed by se e al au ho s [23–25]. These condi ions, as well as he names o each dosage, a e lis ed in Table 4. The mixing mois u e o op imum mois u e con en (OMC) is c i ical o achie e op imum compac ion. Acco ding o p e- ious esea ch, he de e mina ion o his mois u e con en is usually pe o med by means o he UNE-103500 s anda d o modified P oc o es [26] o hei equi alen s acco ding o ASTM D698-12 s anda d [27]. In his case, ou P oc o es s ha e been p epa ed o wo ypes o s abiliza ion and o he cases o 100% glass and no glass subs i u ion, shown in Fig. 3. In Fig. 3A and B, i can be seen ha he mois u e con en s a e e y simila o all cases and a e a ound 8%, excep o he cemen wi h glass, which is educed o 7%. Since he di e - ences a e so small and conside ing he di ficul y o p ecisely con olling his ma gin du ing manu ac u e, i was decided o wo k wi h an OMC equal o 8%. Once he s a ing pa ame e s we e defined, he manu ac- u e and cu ing o he es specimens was de eloped. Fi s , each soil and glass ac ion we e o en-d ied o 24 h a less han 100◦C, so ha he mine alogical componen s we e no a ec ed and o ensu e ha all mix u es s a ed om he same mois u e con en be o e mixing. The agg ega e ac ions co esponding o each dosage we e hen d y-mixed, and he s abilize (cemen o lime) was added o achie e a uni o m mix u e. Acco ding o he d y weigh p oduced and ha ing p e iously checked he mois u e con en o he agg ega es, he 4 b o l e í n d e l a s o c i e d a d e s p a ñ o l a d e c e á m i c a y i d i o 6 4 (2 0 2 5) 100442 Fig. 1 – X- ay di ac og am o he AFN clay. Fig. 2 – Pa icle size dis ibu ion o soil (A) and soil wi h p ocessed glass (B). Table 3 – Chemical analysis o glass. Elemen s SiO2Na2O CaO MgO Al2O3K2O SO3Fe2O3TiO2MnO P2O5LOI % 72.21 13.05 9.98 3.46 0.76 0.34 0.3 0.26 0.07 0.03 0.01 0.46 D.L. 0.02 0.01 0.03 0.02 0.01 0.01 0.01 0.04 0.01 0.01 0.01 C.L. 0.03 0.02 0.05 0.03 0.02 0.02 0.02 0.06 0.02 0.04 0.02 Rel.E. 0.019 0.073 0.0100 0.029 0.011 0.038 0.137 0.023 0.106 0.050 0.026 T aces F Ba S P Zn Pb C S Z Mn Sn Cs Cu Ppm 1211 1200 1076 144 84.8 66.6 64.5 59.5 57.1 52.1 32.2 27 26 D.L.: de ec ion limi ; C.L.: cuan ifica ion limi ; Rel.E.: ela i e e o . b o l e í n d e l a s o c i e d a d e s p a ñ o l a d e c e á m i c a y i d i o 6 4 (2 0 2 5) 100442 5 Table 4 – Dis ibu ion and desc ip ion o each dosage o he expe imen al phase (-R, s ands o e e ence g oup). Ba ch Numbe samples S abiliza ion Glass C-R 6 Cemen (5%) – C-50 6 Cemen (5%) 50% C-75 6 Cemen (5%) 75% C-100 6 Cemen (5%) 100% L-R 6 Lime (5%) – L-50 5 Lime (5%) 50% L-75 6 Lime (5%) 75% L-100 6 Lime (5%) 100% Fig. 3 – Op imum mois u e con en and maximum densi y o cemen (A) and lime (B). Fig. 4 – P epa a ion o samples om p isma ic shape moulds. 6 b o l e í n d e l a s o c i e d a d e s p a ñ o l a d e c e á m i c a y i d i o 6 4 (2 0 2 5) 100442 necessa y wa e was added un il he OMC was eached. The mixing was ca ied ou in a pan conc e e mixe ha allows wo king adequa ely wi h low wa e –s abilize a ios and d ie ex u es. The mix u e was hen compac ed in he moulds in ou laye s o abou 5 cm hickness. Once he fi s 3 laye s had been compac ed, a plas ic film was applied be o e he las laye was compac ed. In his way, a 15 × 15 × 15 cm es specimen, called A, and ano he 15 × 15 × 5 cm specimen wi h he same compac ion, called B, could be ob ained o he es s (Fig. 4). In o de o main ain uni o mi y in he a e o compac ion o all he specimens, he p ocedu e de eloped by he au ho s [28] was ollowed, bu adap ed o he use o a jackhamme , o which he me hodology desc ibed by [24,29] is aken as a e e ence. Basically, i consis s o es ablishing a ela ionship be ween he specific compac ion ene gy o he s anda d P oc- o es and ha o he mechanical ools used. Fo his pu pose, he hamme manu ac u e ’s da a we e conside ed, wi h he numbe o blows (b) pe minu e (nb) being 26 b/min, acco d- ing o an in e media e speed configu a ion, and he ene gy pe impac being j = 1 J. By equa ing he specific compac ion ene gies om he P oc o and he expe imen , Eq. (1) can be ob ained, which desc ibes he ime equi ed o compac a 5 cm laye o ma e ial wi h he hamme desc ibed. In ou case min = 14.26 s, so he compac ion ime was con olled a 15 s pe laye , du ing which he hamme , which had a compac ion su ace o 5 × 5 cm, co e ed he en i e su ace o 15 × 15 cm o he es specimen. min =Vm VOMC nOMC nb m × g × h j, (1) Vmbeing he olume o he specimen laye (m3), VOMC he olume o he s anda d P oc o es laye (m3), nOMC he num- be o blows pe P oc o laye – which is 26 blows, nbis he numbe o blows pe minu e o he hamme , m is he mass o he P oc o hamme (2.5 kg), g is he accele a ion o g a - i y in m s−2, h is he heigh a which he P oc o hamme alls (0.305 m) and j is he ene gy pe blow o he hamme (Joules). A e finishing h ee successi e laye s, which o med he ype A es sample, be o e pou ing he mix u e, he plas ic film was placed o sepa a e he ou h 5 cm laye , hus defining he ype B es sample. A e demoulding, he samples we e le o d y du ing 28 days unde he same en i onmen al condi ions (20 ± 2◦C and 65 ± 5% ela i e humidi y). The es s ca ied ou on each ype o specimen a e desc ibed below. Specimens B we e in ended o es s o de e mine he bulk densi y and open po osi y, by means o a wa e sa u a ion me hod in acuum, ollowing he p ocedu e p o ided in UNE- EN-1936 s anda d [30]. The he mal conduc i i ies o he samples we e de e - mined by using a es se -up manu ac u ed by PHYWE Sys eme GmbH & Co. KG [31]. This same se -up has been used by se e al esea che s o measu e he he mal conduc- i i y o conc e es [32] and ea h building ma e ials [33]. The equipmen consis s o a 40 cm side house, he mally insula ed, which con ains a hea sou ce in i s in e io . The side walls o he house ha e 21 cm squa e openings, and he samples o be es ed can be fixed om he inside agains he openings using ensioning sc ews. Since he on al a ea o ou samples ( ype B specimens, 15 × 15 cm2) was smalle han he ape u es on he side walls, he samples we e moun ed in a 4 cm hick polyu e hane ame. Du ing he expe imen s, ype K he mocouples we e used o measu e he ai empe a u e in he labo a o y (Tai ), he empe a u e a he cen e o he ex e nal su ace o he sam- ple (Tou ) and he empe a u e a he cen e o he in e nal su ace o he sample (Tin). A iny amoun o he mal g ease (HY710, Shenzhen Halnziye Elec onics Co.) was applied a he con ac poin s be ween he he mocouple ips and he solid su aces o imp o e he he mal con ac . All empe a u es we e eco ded o e ime using a high- esolu ion da a logge (TC-08, Pico Technology) connec ed o a PC, un il s eady-s a e condi ions we e eached (6–8 h). A ha momen , he hea flux h ough he sample pe uni a ea q (W/m2) can be ob ained as q =Tou − Tai Rs =Tin − Tou e/(2) whe e Rsis he su ace he mal esis ance o he ai bounda y laye nex o he sample, and e and  a e he hickness and he he mal conduc i i y o he sample, espec i ely. He e, acco d- ing o he s anda d ISO 6946:2017 [34], he con en ional alue Rs= 0.13 m2K/W o ho izon al hea flow h ough a plane su - ace will be assumed. The he mal conduc i i y o he sample can hen be ob ained as,  =e Rs ×Tou − Tai Tin − Tou (3) Ul asonic pulse eloci y (UPV) es s we e pe o med on A samples wi h a Pundi Lab sys em om P oceq company, equipped wi h wo 54 kHz piezoelec ic senso s. The p o- cedu es es ablished in he UNE-EN 12504-4 s anda d we e ollowed in his es ing [35]. Since en eadings a e aken a each loca ion, a a iabili y ange o ±2% om he mean alue was he e o e aken. A e his check, some a ypical alues we e disca ded, so ha he a e age o all he fil e ed ead- ings in each UPV di ec ion and loca ion s udied was ob ained. This c i e ion was aken in o accoun o de e mine he ul a- sonic pulse eloci ies UPV-X and UPV-Y, o hose di ec ions pe pendicula o he compac ion di ec ion, and UPV-Z o he compac ion di ec ion. In addi ion, h ee heigh s we e di e en- ia ed in he X–Y plane, depending on whe he he ansduce s we e loca ed a he base (B), in he middle (M) o a he op (T) o specimen A (Fig. 5). Measu emen s a 14 and 28 days we e aken in o de obse e and check he e olu ion and ce ain ends [28]. Howe e , he mechanical es was only possible o ca y ou a 28 days, hence lec u es o UPV a 14 days will se e as a simple checking o he in e nal e olu ion o he samples. Table 5 desc ibes he lis o UPV a iables ini ially conside ed in his esea ch. The comp essi e s eng h o A- ype specimens was ob ained a e cu ing o 28 days. The comp ession es s we e ca ied ou using a uni e sal monoaxial es ing machine. The loading his o y was es ablished conside ing UNE- EN 14580:2006 S anda d [36]. The ampli udes o he loading–unloading p ocesses we e defined by load le els, bu hey we e displacemen con olled a 1 mm/min a e. The UPV measu emen s in he cemen and lime samples, and he co esponding 50%, 75% and 100% subg oups, we e used o de e mine he dynamic modulus o elas ici y “MOE” b o l e í n d e l a s o c i e d a d e s p a ñ o l a d e c e á m i c a y i d i o 6 4 (2 0 2 5) 100442 7 Fig. 5 – Dis ibu ion o loca ion o senso s o UPV and A- ype specimens. Table 5 – Desc ip ion o he di e en UPV eadings aken in acco dance wi h loca ion, age, and di ec ion. UPV XT14 UPV YT14 UPV XM14 UPV YM14 UPV XB14 UPV YB14 UPV ZM14 UPV XT28 UPV YT28 UPV XM28 UPV YM28 UPV XB28 UPV YB28 UPV ZM28 Loca ion Top • • • • Middle • • • • • • Bo om • • • • Age (days) 14 14 14 14 14 14 14 28 28 28 28 28 28 28 Axis X Y X Y X Y Z X Y X Y X Y Z E (MPa) acco ding o Eqs. (4) and (5), which depend on UPV (m/s) and densi y  (kg/m3). The ela ionship be ween UPV and MOE in ammed ea h ma e ials has been alida ed by p e ious esea ch [37]: E =p 2 K, (4) K =1 − (1 + ) (1 − 2 ), (5) whe e is Poisson’s a io, whose alue was se a 0.35 as p o- posed by o he au ho s [37,38]. Finally, a s a is ical analysis o he esul s (independen samples T-S uden es ) is ca ied ou o es ablish he possible exis ence o s a is ically significan di e ences in he physical and mechanical alues be ween he g oups o e e ence speci- mens and hose co esponding o he di e en deg ees o glass subs i u ion. I he es is posi i e, i could be a fi med ha he subs i u ion o sand by glass has a s a is ically decisi e influence on he analysed p ope y. Resul s and discussion Physical esul s Table 5 shows he desc ip i e s a is ics o he bulk densi y and open po osi y alues ob ained o he di e en mixes. Excep o he case o po osi y o he cemen -based mixes, he educed s anda d de ia ion and coe ficien o a ia ion alues desc ibe a ep esen a i e and uni o m da a se . I can also be s a ed ha he a e age alues a e as expec ed o his ype o ma e ial [24,39], he densi ies being simila o hose es ab- lished by he P oc o es (Fig. 2) o he dosages wi hou glass and 100% eplacemen . Fig. 6 shows ha in he case o cemen , he median densi y inc eases sligh ly wi h inc easing he deg ee o glass subs i u ion, eaching 2.01 g/cm3. Consequen ly, he po osi y dec eases o a minimum o 21.18%, which defines a low po osi y wall, in line wi h he minimum ange es ablished o bo h new [40] and his o ical [41] compac ed soil-based ma e ials. In con as o his end, he beha iou o he lime- 8 b o l e í n d e l a s o c i e d a d e s p a ñ o l a d e c e á m i c a y i d i o 6 4 (2 0 2 5) 100442 Fig. 6 – Rep esen a ion o d y densi y (A) and open po osi y (B) acco ding o he ype o s abiliza ion me hod and he pe cen age o glass. Table 6 – S a is ical esul s o physical p ope ies o samples. N Densi y (g/cm3) Po osi y (%) AV SD VC AV SD VC C-R 5 1.96 0.08 0.04 23.50 2.87 0.12 C-50 5 1.96 0.04 0.02 23.79 2.23 0.09 C-75 5 1.99 0.08 0.04 24.23 2.21 0.09 C-100 5 2.01 0.03 0.02 21.18 2.40 0.11 L-R 6 1.91 0.04 0.02 26.72 0.98 0.04 L-50 5 1.92 0.03 0.02 25.77 0.99 0.04 L-75 4 1.85 0.03 0.01 28.86 1.05 0.04 L-100 6 1.82 0.02 0.01 27.56 0.86 0.03 N: numbe o da a; AV: a e age; SD: s anda d de ia ion; VC: a ia ion coe ficien . based specimens shows a p og essi e educ ion in densi y as a highe pe cen age o glass eplacemen is used, down o a minimum o 1.82 g/cm3. The po osi y, howe e , p esen s he minimum a he 50% subs i u ion (L-50: 25.77%), being in any case always highe han hose using cemen . F om his dosage o glass onwa ds, he samples inc ease hei po osi y un il hey each alues o mo e han 30% o L-75. The e o e, wi h ega d o he physical beha iou , he e seems o be a di e en ial esponse depending on he s abilize used, and he deg ee o glass subs i u ion induces, om a desc ip i e poin o iew, an influence on densi y and po osi y (Table 6). The s a is ical analysis on he physical p ope ies shows ha when cemen is conside ed, he e is no significan a ia- ion in densi y and po osi y o any o he glass subs i u ions (C-50, C-75 and C-100) wi h espec o he e e ence (C-R). How- e e , when lime is used, he e a e significan a ia ions in densi y o L-75 [ (8) = 26.127, p = .000] and L-100 [ (10) = 4.6989, p = .0008] and in po osi y o L-75 [ (8) = −3.4699, p = .008]. This means ha , when cemen is used, i canno be s a is ically p o en ha he subs i u ion o glass has a decisi e influ- ence on he physical p ope ies, al hough, as shown in Fig. 5, he e is a sligh p og essi e inc ease in he densi y a e ages and consequen educ ions in po osi y. When c ushed glass is used, pozzolanic eac ions can occu in he p esence o he calcium hyd oxide o he cemen , which gene a es new com- pounds (hyd a ed calcium silica es) ha a e deposi ed in he po es o he ma e ial [42]. When using lime, as he e a e mo e p onounced a ia ions a highe glass subs i u ions (75% and 100%), i is s a is ically possible o s a e ha glass can deci- si ely al e he physical p ope ies. Mechanical esul s Table 7 shows he desc ip i e s a is ics o he simple com- p essi e s eng h alues a 28 days ob ained o he di e en pe cen ages o glass subs i u ion, acco ding o each ype o binde . In all cases, he mechanical s eng h is highe o cemen , as has been epo ed in o he s udies [43], wi h he di e ence be ween he wo being o he o de o 100% and eaching mo e han 200% when he glass subs i u ion is 100%. In gene al, he dispe sion o esul s is as expec ed o his ype o he e ogeneous ma e ials, wi h CVs be ween 15 and 25%, excep in he case o C-75 and C-100, which ise o 30% [28,44,45], while o lime (Fig. 7A) he dispe sion is smalle , wi h he pe cen iles being mo e clus e ed a ound he mean o each g oup. Rega ding he use o lime, i is obse ed (Fig. 7) ha he e is a maximum UCS in he subs i u ion L-75, wi h an a e - age o 1.83 MPa, he s anda d de ia ion and he coe ficien o a ia ion being lowe han in he case o cemen . This b o l e í n d e l a s o c i e d a d e s p a ñ o l a d e c e á m i c a y i d i o 6 4 (2 0 2 5) 100442 9 Table 7 – S a is ical esul s o unconfined comp ession s eng h o samples. N UCS (MPa) AV SD VC  % C-R 6 2.19 0.50 0.23 – C-50 6 3.00 0.69 0.23 – C-75 6 3.90 1.20 0.31 – C-100 6 4.07 1.23 0.30 – L-R 6 0.78 0.30 0.38 109 L-50 5 1.61 0.39 0.24 86 L-75 6 1.83 0.25 0.14 113 L-100 6 1.31 0.21 0.16 210 N: numbe o da a; AV: a e age m/s; SD: s anda d de ia ion; VC: a ia ion coe ficien ;  %: pe cen age di e ence o mean alues be ween cemen and lime samples. Fig. 7 – Rep esen a ion o UCS acco ding o he ype o s abiliza ion me hod and he pe cen age o glass (A). Rela ion be ween UCS and densi y acco ding o he ype o chemical s abilize (B). end is no ollowed by cemen , which shows a p og essi e inc ease in mechanical s eng h un il comple e subs i u ion wi h glass. The be e mechanical beha iou o he cemen specimens can be ela ed o he highe densi y and lowe po osi y (Figs. 6 and 7B). As o he s udies ha e epo ed, he fine pa icles o glass p o ide highe adhesion due o he poz- zolanic e ec [42,46,47]. The hypo hesis o he o ma ion o hyd a ed neosilica es by alkaline ac i a ion can also be con- side ed. Acco ding o Ha ison e al. [48] alkaline ac i a ion occu s wi h glass when i s size is less han 20 ␮m, which imp o es he mechanical beha iou when he chemical eac- ion akes place. In addi ion, he use o c ushed glass p o ides an agg ega e wi h angula shapes ha imp o es mechanical pe o mance o agg ega e compac ion [49] and, oge he wi h he o ma ion o he hyd a ed componen s o he cemen , allows highe le els o mechanical s eng h o be achie ed. Acco ding o he UCS s a is ical s udy, when conside - ing he use o cemen , he e is significan a ia ion o 75% glass subs i u ion, C-75 [ (10) = −3.2205, p = .0092] and C-100 [ (10) = −3.4587, p = .0061]. Fo lime, he a ia ion is mo e p onounced in all glass subs i u ion g ades, L-50 [ (9) = −3.9959, p = .0031], L-75 [ (10) = −6.6071, p = .00012] and L- 100 [ (10) = −3.5738, p = .0051]. The e o e, i can be s a ed ha he pa ial subs i u ion o agg ega es by c ushed glass has a di ec ela ionship wi h he change in mechanical beha iou and ha i is in lime whe e hese changes, a he s a is ical le el, a e mo e app eciable. The mal p ope ies Fig. 8 shows he a e age alues o he he mal conduc i i y (l) o each dosage o c ushed glass, showing a g adual educ ion wi h inc easing glass con en , excep in he pa icula case o he use o lime o L-100, which emains significan ly he same as o L-75. The mal conduc i i y o d y-s a e, non-glass ammed ea h wi hou addi ions [50,51] is in he ange o ha epo ed in his esea ch. On he o he hand, glass has a epo ed he mal conduc i i y o 0.4–0.9 W/mK [52], depending on i s composi ion, being significan ly lowe han ha no mally epo ed o he ammed ea h (0.6–1.6 W/mK, acco ding o Re . [51]), i is possible ha he use o glass educes he alue o 16 b o l e í n d e l a s o c i e d a d e s p a ñ o l a d e c e á m i c a y i d i o 6 4 (2 0 2 5) 100442 [53] V. Flo es-Alés, J.M. Alducin-Ochoa, J.J. Ma in-del-Rio, M. To es-González, V. Jiménez-Baya i, Physical–mechanical beha iou and ans o ma ions a high empe a u e in a cemen mo a wi h was e glass as agg ega e, J. Build. Eng. 29 (2020) 101158, h p://dx.doi.o g/10.1016/J.JOBE.2019.101158. [54] Q.B. Bui, J.C. Mo el, Assessing he aniso opy o ammed ea h, Cons . Build. Ma e . 23 (2009) 3005–3011, h p://dx.doi.o g/10.1016/j.conbuildma .2009.04.011. [55] J.D. Rod íguez-Ma iscal, M. Zieli´ nska, M. Rucka, M. Solís, Aniso opy and compac ion g adien assessmen on ammed ea h specimens h ough sonic omog aphy app oach, Eng. S uc . 309 (2024) 118058, h p://dx.doi.o g/10.1016/j.engs uc .2024.118058. [56] J.R. Rosell, I.R. Can alapied a, Simple me hod o dynamic Young’s modulus de e mina ion in lime and cemen mo a s, Ma . Cons . 61 (2011) 39–48, h p://dx.doi.o g/10.3989/mc.2010.53509. [57] J.D. Rod íguez-Ma iscal, J. Cani ell, M. Solís, E alua ing he pe o mance o sonic and ul asonic es s o he inspec ion o ammed ea h cons uc ions, Cons . Build. Ma e . 299 (2021) 123854, h p://dx.doi.o g/10.1016/j.conbuildma .2021.123854.