Experimental study using ASTM and BS standards and model evaluations to predict the compressive strength of the cement grouted sands modified with polymer

摘要

The present article discusses the impact of the different grain sizes of sand on the ultimate stress of hand-mixed cement grouted sand modified with polycarboxylate ether-based polymer using two different test standards (ASTM and BS). The fresh and hardened properties of cement grouted sands modified with polymer up to 0.16 % of the weight of cement were tested and quantified. Five types of sand with different grain sizes were used in this study. Adding polymer decreased the water/cement ratio (w/c) by 21.9–54.1%, and it kept the flow time of the cement-based grout in the range of 18–23?s. Adding polymer creates an amorphous gel that fills the porous between the cement particles, which causes a reduction in the voids, porosity and enhanced the dry density of the cement; subsequently, the compression strength of the cement-grouted sands increased significantly. Linear and nonlinear approaches were employed to estimate the compressive strength of cement grouted sand with a different grain size of sand, w/c, amount of polymer, and curing age. The compressive strength of the cement grouted sands following the BS standard was 71 % larger than the compression strength of the same mix using the ASTM standard.