Strength, thermal conductivity and sound absorption of cellular lightweight high calcium fly ash geopolymer concrete

Abstract

In this research, the effects of foam content on mechanical property, thermal property and sound absorption of cellular lightweight geopolymer concrete (CLGC) were studied. The geopolymer mixtures were made with 15 M NaOH solution, sodium silicate/NaOH ratio (NS/NaOH) of 1.00, sand/ash ratio of 1.25, liquid/fly ash ratio of 0.4. The foam contents were varied from 2-12 %wt. The 28-day compressive strength of CLGCs of 2.7-57.8 MPa, unit weight of 844-2100 kg/m3, water absorption of 1.36-31.25%, porosity of 2.82-49.42%, thermal conductivity of 0.13-1.62 W/mK, and sound absorption coefficients of 0.05-0.5 were obtained. The CLGCs with 4% foam content, 28-day compressive strength of 38.9 MPa and unit weight of 1815 kg/m3is suitable for structural lightweight concrete complying to the requirements of ASTM C330/C330M-17a. Whereas the mix with 8 and 10 % foam contents with compressive strengths of 7.60 and 6.1 MPa, and unit weights of 1210 and 1060kg/m3are suitable for use as masonry lightweight concrete block in accordance with ASTM C331/C331M-17.

Keywords

• cellular lightweight geopolymer concrete
• mechanical property
• thermal property
• sound absorption