Bentonite as a natural additive for lime and lime–metakaolin mortars used for restoration of adobe buildings

Andrejkovičová, S.; Alves, Carlos; Velosa, A. L.; Rocha, Fernando

doi:10.1016/j.cemconcomp.2015.04.005

Cited by 43 publications

(13 citation statements)

References 38 publications

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“…When NaCl and/or gypsum were incorporated in this study, hydrotalcite was mostly removed, and the use of NaCl ( , which is known as a strength enhancing material by filling pores [12,37]. These reaction products have often been observed in earlier studies of construction binders containing chloride [13,[38][39][40] or sulfate sources [12,41,42].…”

Section: C-s-h Hydrotalcite Ca(oh) 2 Ettringite Hydrocalumitementioning

confidence: 82%

Gypsum-Dependent Effect of NaCl on Strength Enhancement of CaO-Activated Slag Binders

et al. 2018

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This study explores the combined effect of NaCl and gypsum on the strength of the CaO-activated ground-granulated blast furnace slag (GGBFS) binder system. In the CaO-activated GGBFS system, the incorporation of NaCl without gypsum did not improve the strength of the system. However, with the presence of gypsum, the use of NaCl yielded significantly greater strength than the use of either gypsum or NaCl alone. The presence of NaCl largely increases the solubility of gypsum in a solution, leading to a higher concentration of sulfate ions, which is essential for generating more and faster formations of ettringite in a fresh mixture of paste. The significant strength enhancement of gypsum was likely due to the accelerated and increased formation of ettringite, accompanied by more efficient filling of pores in the system.

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Section: C-s-h Hydrotalcite Ca(oh) 2 Ettringite Hydrocalumitementioning

confidence: 82%

Gypsum-Dependent Effect of NaCl on Strength Enhancement of CaO-Activated Slag Binders

et al. 2018

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“…The ASR causes the capillary pores to be cracked [36]. As the cracks and voids grow larger, the cracks grow in the size of tens to hundreds of millimeters, which can be measured using 3D-CT without damaging the sample as performed by authors [14]. However, as the porcelain insulator is a composite material of metal, cement, and ceramic, it is not easy to measure the cracks because of X-ray scattering.…”

Section: Resultsmentioning

confidence: 99%

“…The method of diagnosing the life of cement includes measuring the pH variations by employing the universal indicator. The deterioration behavior of cement in the porcelain insulators is estimated using a universal indicator to observe the pH variation with respect to age [12][13][14]. The initial pH of the cement is 12-13 indicating alkaline characteristics.…”

Section: Introductionmentioning

confidence: 99%

Analysis of Cement Deterioration in Outdoor High-Voltage Insulator

et al. 2019

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Suspension type porcelain insulators used in overhead transmission lines comprise metal, ceramic, and cement. The deterioration of cement can lead to mechanical separation. For the degradation analysis, varied sizes of pores ranging from a few µm (capillary pores) to tens to hundreds of mm (detectable by naked eyes) were considered. Cracks that were hard to view with naked eyes were identified by staining with a fuchsine solution. The hydrogen ion concentration and pH value indicate the extent to which the cement is deteriorated. The longer the cement is used, the lower its pH value. High mechanical strength is considered an important advantage of porcelain insulators, and it may decline, if the cement is used for a longer period of time. Water ingress may also occur, resulting in expansion, due to the rehydration of the cement. The process and mechanism of expansion of cement, due to infiltration of water were described. As a method of analysis, a universal indicator was employed to evaluate the pH changes in cement. It was observed that the pH value was 12-13 for new products. However, for products that were used for 52 years, the pH value was under 7, which indicated an acidic tendency, due to deterioration.

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“…Svojstva kao što su velika specifična površina, uniformna poroznost, dobra termička stabilnost, pucolanska aktivnost imaju prednosti pri primeni ovih glina u vezivima, betonima i malterima. Na taj način, zeolit i bentonit ne samo da imobilizuju teške metale, njihov dodatak uslovljava ubrzanje hidratacije cementa, povećanje ranih mehaničkih čvrstoća, smanjenje zapreminske mase (lakša konstrukcija), smanjenje autogenog skupljanja i mikro-pukotina, efikasniji mehanizam sušenja, ravnije površine kod završnih maltera, smanjenje/eliminisanje penetracije hlorida, sulfatne korozije, [13][14][15]. U ovom radu je razmatran uticaj tri mineralna dodatka (zeolit, bentonit, leteći pepeo) na fizičko-hemijska i mehanička svojstva maltera.…”

Section: Uvodunclassified

Properties and performances of mortars with primary and secondary mineral additives applied as cement replacement

Terzić¹,

Mijatović²,

Miličić³

et al. 2018

Tehnika

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ZAGORKA М. RADOJEVIĆ, Institut za ispitivanje materijala, Beograd Mineralni dodaci se ekstenzivno koriste kao zamena za cement u građevinskim betonima i malterima. Leteći pepeo je jedan od najčešće primenjivanih dodataka koji unapređuje reološka, mehanička i termička svojstva materijala. Međutim, ovaj industrijski nusprodukat sadrži teške metale zbog čega je neophodna optimizacija njegove dozaže pri dizajnu maltera. Glineni materiali kao što su zeolit i bentonit svojim sorpcionim mehanizmima mogu da preduprede migraciju toksičnih elemenata iz pepela imobilišući ih unutar strukture. U ovom radu eksperimentalno su ispitana tri različita maltera pripremljena na bazi Portland cementa, rečnog peska i kombinacije mineralnih dodataka-letećeg pepela, zeolita i bentonita. Malter M1 sadržao je sva tri dodatka u odnosu 1:1:1, malter M2 je sadržao zeolit i bentonit u odnosu 1:2, dok je odnos zeolita i bentonita u malteru M3 bio 2:1. Cilj istraživanja je bio da se ispita uticaj mineralnih dodataka na fizičko-hemijska, termička i mehanička svojstva maltera. Primenjene su instrumentalne metode-X-ray difrakcija, diferencijalno termijska i dilatometrijska analiza i FTIR spektroskopija. Rezultati istraživanja su ukazali da se primenom ovih mineralnih dodataka mogu dobiti ekonomični malteri sa dovoljno dobrim performansama.

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Bentonite as a natural additive for lime and lime–metakaolin mortars used for restoration of adobe buildings

Cited by 43 publications

References 38 publications

Gypsum-Dependent Effect of NaCl on Strength Enhancement of CaO-Activated Slag Binders

Gypsum-Dependent Effect of NaCl on Strength Enhancement of CaO-Activated Slag Binders

Analysis of Cement Deterioration in Outdoor High-Voltage Insulator

Properties and performances of mortars with primary and secondary mineral additives applied as cement replacement

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