Amirkabir University of Technology Amirkabir Journal of Civil Engineering 2588-297X 54 10 2022 12 22 Comparing the effects of two alkaline activators of sodium hydroxide and calcium carbide residue on geopolymeric stabilization of clay soils Comparing the effects of two alkaline activators of sodium hydroxide and calcium carbide residue on geopolymeric stabilization of clay soils 3923 3942 4841 10.22060/ceej.2022.20790.7527 FA Meysam Pourabbas Bilondi Department of Civil Engineering, University of Gonabad 0000-0002-9048-1607 Mohammad Mohsen Toufigh Department of Civil Engineering, Shahid Bahonar University of Kerman Vahid Toufigh Faculty of Civil and Surveying Engineering, Graduate University of Advanced Technology, Kerman, Iran Journal Article 2021 11 17 <span style="letter-spacing: .05pt;">Nowadays, the Ordinary Portland Cement (OPC) industry causes extensive environmental consequences due to consuming huge amounts of fossil fuels. This necessitated researchers to introduce a novel group of binders called “Geopolymer cements” or “Green cements” with higher performance and lower pollution compared to the OPC. Thus, in this research, the effect of using two types of alkaline activators such as sodium hydroxide (NaOH) and calcium carbide residue (CCR), for the stabilization of clay soil (CL) has been investigated. Initially, the chemical compositions of soil, recycled glass powder, calcium carbide residue, and sodium hydroxide were obtained via X-ray fluorescence (XRF) test. Then, the mechanical behavior of different unstabilized, geopolymer-stabilized, and OPC-stabilized samples has studied using the unconfined compressive strength (UCS) test. The effects of several parameters such as the type and concentration of alkaline activators and the curing times (7, 28, and 91 days on the UCS and failure strain of samples have been assessed. Moreover, in order to study the microstructure of samples, scanning electron microscope (SEM) images and energy dispersive X-ray (EDX) analysis of selected samples have been used. Results showed the effective stabilization of soil geopolymer, using both alkaline activators. However, the CCR will be more appropriate if environmental and economic problems are considered.</span> <span style="letter-spacing: .05pt;">Nowadays, the Ordinary Portland Cement (OPC) industry causes extensive environmental consequences due to consuming huge amounts of fossil fuels. This necessitated researchers to introduce a novel group of binders called “Geopolymer cements” or “Green cements” with higher performance and lower pollution compared to the OPC. Thus, in this research, the effect of using two types of alkaline activators such as sodium hydroxide (NaOH) and calcium carbide residue (CCR), for the stabilization of clay soil (CL) has been investigated. Initially, the chemical compositions of soil, recycled glass powder, calcium carbide residue, and sodium hydroxide were obtained via X-ray fluorescence (XRF) test. Then, the mechanical behavior of different unstabilized, geopolymer-stabilized, and OPC-stabilized samples has studied using the unconfined compressive strength (UCS) test. The effects of several parameters such as the type and concentration of alkaline activators and the curing times (7, 28, and 91 days on the UCS and failure strain of samples have been assessed. Moreover, in order to study the microstructure of samples, scanning electron microscope (SEM) images and energy dispersive X-ray (EDX) analysis of selected samples have been used. Results showed the effective stabilization of soil geopolymer, using both alkaline activators. However, the CCR will be more appropriate if environmental and economic problems are considered.</span> https://ceej.aut.ac.ir/article_4841_05ee45de8d877c3949760a94fa691533.pdf