Influence of expanded vermiculite powder and silica fume on properties of foam concretes

Köksal, Fuat; Şahin, Yuşa; Gençel, Osman

doi:10.1016/j.conbuildmat.2020.119547

Cited by 86 publications

(26 citation statements)

References 74 publications

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“…As can be seen, the char yield of vermiculite was around 98% and one-step weight loss was observed around 70–100°C due to the removal of absorbed moisture. 62,63 As previously given in the literature, SEBS is relatively stable up to 400°C. 64,65 As shown in Figure 8(a) and Table 3, around 5 wt% weight loss was observed at 400°C and thermal degradation accelerated by exceeding 410°C.…”

Section: Resultssupporting

confidence: 60%

Expanded vermiculite-filled flexible polymer composites

Cetin

Toprakçi

Taşkın

et al. 2021

Journal of Elastomers & Plastics

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This study focuses on the fabrication and characterization of vermiculite-filled flexible polymer composites. Exfoliated vermiculite was incorporated into triblock thermoplastic elastomer copolymer, styrene- b-(ethylene- co-butylene)- b-styrene (SEBS), at various levels from 1 to 15 wt% by a high shear mixer. The composite films were obtained by the combination of solvent casting and compression molding. The morphological, structural, thermal, and mechanical properties and contact angle of the composites were determined. Some micro-morphological differences were observed between the samples and the difference was assumed to be caused by high shear mixing and filler concentration. High shear mixing was found effective in terms of the detachment of vermiculite layers at all concentrations. However, at low filler loading, that behavior was more obvious. At 1 wt% filler concentration, mechanical properties increased that was probably caused by good filler-matrix interaction stemmed from smaller particle size. At higher vermiculite concentrations, fillers found to show agglomerations that led to a decrease in mechanical strength and strain at break. Elastic and secant modulus showed an increasing trend. Contact angle measurements were carried out to determine the oleophilic character of the samples. An increase in the vermiculite content resulted in higher oleophilic character and the lowest contact angle was obtained at 15 wt% VMT loading. In addition to these, thermal stability, thermal dimensional stability and flame retardancy were improved by the incorporation of VMT. 15 wt% vermiculite-filled sample showed the best performance in terms of thermal stability and flame retardancy.

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Section: Resultssupporting

confidence: 60%

Expanded vermiculite-filled flexible polymer composites

Cetin

Toprakçi

Taşkın

et al. 2021

Journal of Elastomers & Plastics

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“…Pozzolanic materials react with calcium hydroxide (CH) to form a calcium silicate hydrate gel (CSH), and CSH provides a less corrosive environment, which helps to improve the durability of composite materials and makes it dense [22][23][24][25]. SF has been used as a pozzolanic material instead of cement to produce foamed concrete, which can compensate for the negative impact of vermiculite on mechanical values [26]. It is found that SF fills the pores and makes the structure dense during the hardening stage, when it is used to improve the performance of foam concrete or cement-based composites [27][28][29].…”

Section: Introductionmentioning

confidence: 99%

Strength Characteristics and Microstructure of Cement Stabilized Soft Soil Admixed with Silica Fume

Jiang

Wang

et al. 2021

Materials

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Soft soil improvement is an important subject in civil engineering, and searching for an effective admixture is an important research. Silica fume (SF) is a kind of recycled material, it can be used in engineering as a pozzolanic material. The main objective of this study is to assess the effectiveness of industrial waste silica fume (SF) as an admixture to improve the cement stabilized soft soil. The unconfined compressive test (UCT) and scanning electron microscopy (SEM) test of cement stabilized soil with different SF contents and different curing times have been carried out. UCT after 28 days revealed that the addition of SF can effectively increase the strength of cement stabilized soil and reduce the amount of cement, and 1.5% SF content is considered optimum, excessive SF will not further increase the strength. SF helped to accelerate the cement hydration reaction and significantly improve the early-age strength of stabilized soil even at 3 days, which can improve construction efficiency in actual projects. SEM analyses shows that the proper SF content could make the hydration product calcium silicate hydrate gel (CSH) fill the pores and increase the strength of the material, but excessive SF will increase the large pores content of the material and reduce the strength. This provided a basis for application of SF in improving soft soil.

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“…Köksal et al stated that as the foam content increased, the porosity and water absorption rate increased, but the density decreased (Koksal et al 2020). As the foam content increases, the number of air bubbles in the mixture rises.…”

Section: Results and Dıscussionsmentioning

confidence: 99%

Microstructure and durability properties of lightweight and high-performance sustainable cement-based composites with rice husk ash

Kaplan

Elmekahal

2021

Environ Sci Pollut Res

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Sustainable solutions are investigated to reduce the environmental damage caused by greenhouse gases and CO 2 emissions. Cement is a construction material responsible for greenhouse gases and CO 2 emissions. Thus, CO 2 emissions are reduced by using replacement materials such as rice husk ash instead of cement. This study investigated the durability and mechanical properties of lightweight and high-performance, sustainable cement-based composites. A foaming agent was used to reducing the unit weight of the mixtures. Also, pumice powder (PP) and rice husk ash (RHA) were used to improve cementbased composites' durability and mechanical properties. The density of mixtures varies between 1666-2205 kg/m 3 . The early age strength of the mixes using 12.5% RHA has increased. The mixtures' compressive strength (91-days) with 25% RHA and 50% PP was 46.6 MPa. As the PP content of mixes increased, drying shrinkage values increased. Expansions decrease as the initial compressive strength increases in mixtures exposed to sulfate. As RHA and PP's ratio increased, weight loss decreased in mixes exposed to HCl, while weight loss increased in mixes exposed to H 2 SO 4 . It was determined that the content of CH(OH) 2 is important in mixes exposed to HCl, and impermeability is important in mixes exposed to H 2 SO 4 . It has been observed that the initial compressive strength is also important in mixes exposed to the freeze-thaw effect. As the foam content of the mixes increased, the compressive strength decreased while the drying shrinkage increased. As a result, using up to 25% RHA has increased the performance of cement-based composites.

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Influence of expanded vermiculite powder and silica fume on properties of foam concretes

Cited by 86 publications

References 74 publications

Expanded vermiculite-filled flexible polymer composites

Expanded vermiculite-filled flexible polymer composites

Strength Characteristics and Microstructure of Cement Stabilized Soft Soil Admixed with Silica Fume

Microstructure and durability properties of lightweight and high-performance sustainable cement-based composites with rice husk ash

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