Influence of superplasticizers on the hydration of cement and the pore structure of hardened cement

• Published in: Cement and concrete research Vol. 36; no. 11; pp. 2049 - 2053
• Main Authors: Sakai, Etsuo, Kasuga, Takayuki, Sugiyama, Tomomi, Asaga, Kiyoshi, Daimon, Masaki
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Ltd 01.11.2006; Elsevier Science
• Subjects: Admixture; Applied sciences; Buildings. Public works; Cement concrete constituents; Cements; Dispersion; Exact sciences and technology; Hydration; Materials; Mercury porosimetry; Pore size distribution; Properties of anhydrous and hydrated cement, test methods; X-ray diffraction; Mercury porosimetry; X-ray diffraction; Pore size distribution; Admixture; Dispersion; Hydration; Pore structure; Superplasticizer; Experimental study; X ray diffraction; Pore size; Hardened cement paste; Cement; Chemical composition
• ISSN: 0008-8846; 1873-3948
• DOI: 10.1016/j.cemconres.2006.08.003

This paper describes the influence of various types of superplasticizers such as naphthalene type (β-NS), refined lignin sulfonate type (LS) and polycarboxylate types (P34, S34) on the hydration of cement and the pore structure of hardened cement. Other superplasticizers except β-NS delayed the initial hydration of cement. In any case, it hardly influences the hydration reaction at late stage of cement. The retardation by the addition of superplasticizers is not observed after 28 days of curing. Large pores of 0.1 μm or more for hardened cement with LS or β-NS are larger than those of hardened samples with P34 or S34 cured for 28, 56 and 91 days. This is related to the coagulated structures of fresh cement pastes with various types of superplasticizers. It was presumed that the size of the cluster of aggregated particles became small when S34 or P34 that has a high dispersing ability was added compared to LS or β-NS that has a lower dispersing ability.