Các tính chất kỹ thuật và đặc điểm vi cấu trúc của vữa xây dựng được chế tạo bằng phương pháp kiềm hoạt hóa

Abstract

This paper presents the results of the study on the use of fly ash (FA) and ground granulated blast-furnace slag (GGBFS) in the preparation of construction mortars by alkaline activation method with application orientation for plastering works. The mortar samples were designed with a target compressive strength value of at least 10 MPa at 28 days using different mass ratios of GGBFS/FA (70/30, 50/50, and 30/70) and various concentrations of NaOH solution (6M, 8M, 10M, and 12M). A mixture of NaOH and Na₂SiO₃ solutions was used as an alkaline solution. Characteristics of the mortar samples were assessed including compressive strength, water absorption, drying shrinkage, ultrasonic pulse velocity, and microstructure analysis. A comparison between the properties of the alkali-activated mortar and the traditional cement mortar was performed in this study. Experimental results show that the mortar samples produced using 50 % FA + 50 % GGBFS that activated by the Na₂SiO₃ + NaOH 10M exhibited the most suitable engineering properties among the mixtures according to TCVN 4314:2003. Further, the results of the study demonstrate great potential in producing alkali-activated construction mortar using FA and GGBFS, which can completely replace traditional cement mortar in construction activities, contributing to both saving natural resources and limiting environmental pollution.