Cement

About: Cement is a research topic. Over the lifetime, 68440 publications have been published within this topic receiving 829356 citations.

Self-healing ability of fly ash–cement systems

Abstract: Concrete is susceptible to cracking due to both autogenous and drying shrinkage. Nevertheless, most of these types of cracks occur before 28 days. Because fly ash continues to hydrate after 28 days, it is likely that hydrated products from fly ash may modify microstructure, seal these cracks, and prolong the service life. This research investigates the self-healing ability of fly ash–cement paste. Compressive strength, porosity, chloride diffusion coefficients, hydration reactions and hydrated products were studied. The research focuses on behavior after 28 days. According to the experimental results, the fly ash–cement system has the self-healing ability for cracks that occur from shrinkage. The self-healing ability increased when the fraction of fly ash increased.

Fundamental Characteristics of Cement-Admixed Clay in Deep Mixing

Abstract: This paper examines the compressibility and strength characteristics of high water content cement-admixed clay in deep mixing applications. During curing time, both cement content and total clay water content of the clay–water–cement mixture significantly affect the strength and compressibility of the resulting stabilized clay. To ensure optimum improvement, the selection of an appropriate total clay water content for a mixture with a certain cement content is crucial. Furthermore, the fundamental parameters such as the ratio of after-curing void ratio ( eot ) and cement content ( Aw ) have been found sufficient to characterize the strength and compressibility of cement-admixed clay. The results of unconfined compression and consolidated–undrained tests have proven that the ratio eot ∕ Aw combines together the influences of clay water content, cement content, and curing time as well as curing pressure on the strength of cement-admixed clay. In addition, useful empirical relationships on deep mixing applic...

Isotropic yielding in an artificially cemented soil cured under stress

Abstract: The work simulates, in the laboratory, the formation of a cemented sedimentary deposit in which cement bonding occurs after burial and under geostatic stresses. Isotropic compression tests were carried out on artificially cemented specimens made with variable cement contents. After consolidating the samples to the uncemented normal compression line, the specimens were allowed to cure for 48 h before testing. The curing confining stresses ranged from 50 to 2000 kPa, and were intended to represent soil elements at different depths in the fictitious sedimentary deposit when the cementing occurred. The contribution of the cement bonds to soil compression and the changes in the isotropic yield stress as a function of void ratio and cement content were analysed. The results showed the importance of the void ratio during the formation of cement bonds and also of the degree of cementation for the compressive behaviour of the cemented soil, and demonstrated that the variation in yield stress with void ratio and ce...