Testing and Modeling the Gradually Applying Compressive Stress to Measuring the Strain of Self-Compacted Cement Paste Using Vipulanandan p-q Model

摘要

This study tested and quantified the stress-strain behavior, elastic modulus, and toughness of self-compacted cement paste. The characteristics of self-compacted flowable cement paste modified with two types of polymer up to 0.06 % (dry weight of cement) were investigated. Stress-strain behavior of modified cement with polymer was investigated for different curing times 1, 3, 7, and 28 days. Adding polymers improved the flowability of cement by 7 to 26 %, but it decreased the water/cement ratio (w/c) from 0.5 to 0.29, depending on the polymeric struc-ture and its content. The nonlinear Vipulanandan p-q equation was tested to predict the stress-strain relationship of the modified cement with polymers and was compared with the beta model. When 0.06 % polymers were added to cement, the compressive strength increased by 107 to 257 %. According to polymer types, curing age (t), w/c, and polymer content, the initial elastic modulus (E) of cement also increased by 23 to 240 % with additional polymers. Based on the statistical evaluation tools, the Vipulanandan p-q model predicted the stress-strain relation-ships better than beta model. Linear and nonlinear relationships were used to predict the compressive strength, modulus of elasticity, and toughness of the cement paste as a function of w/c, curing time, and polymer contents.