ผลกระทบของขนาดผงหินปูนต่อสมบัติของมอร์ต้าร์ปอร์ตแลนด์ซีเมนต์ผสมและเถ้าแกลบ

Abstract

Abstract

This paper presented the effect of the particle size of limestone powder (LS) on Portland cement mortar mixed with ground rice husk ash (GRHA). Two different sizes of the LS, 12 and 128 mm, were used to partially replace in Portland cement Type 1 at replacement levels of 5, 10 and 15% by weight of powder materials (Portland cement Type 1, LS and GRHA). GRHA was also used to partially replace in cement at replacement levels of 0, 20 and 40% by weight of powder materials. The water-to-powder materials corresponded to the water requirements that conformed to a flow value at 110% ± 5%. The tested properties were compressive strength, drying shrinkage and expansion in Na₂SO₄ solution with a concentration of 5% wt. The test results showed that the 12 mm-LS could be improved dispersion, resulted in the reduced water requirement, increased early-age compressive strengths, reduced drying shrinkage and expansion under sulfate attack on the mortars. However, the 128 mm-LS resulted reversely in the increased water requirement reduction, lower compressive strengths at the early stage, increased drying shrinkage and increased expansion under sulfate attack.