The use of grinded andesite-sand and foaming-agent to improve the porosity of foam-concrete

¹ CE Department, University of Muhammadiyah Malang, Malang, Indonesia
² Post-graduate, CE Department, University of Muhammadiyah Malang, Malang, Indonesia
³ Senior Manager Research & Development PT. Semen Indonesia, Gresik, Indonesia

^* Corresponding author: erwin_r@umm.ac.id

Abstract

There has been an increase in the demand for the use of green concrete in construction. Foam concrete is a lightweight concrete type that has the characteristics of being lightweight, low-strength, highly porous with a high absorption rate and with good insulation properties. The use of sand smoothed andesite in the manufacture of foam concrete is expected to improve the properties of porous concrete and make it more suitable for use. In this study, 120 mortar cubes with the size of 5 cm was used for the density testing, compressive strength testing and porosity testing of foam concrete. Foam concrete is made by mixing cement, sand andesite of 1:2.75 and w/c 0.7 and a foaming agent, which are respectively 1%,2%, 3%, and 4%. Porosity measurements with the soaking method and the concrete compressive strength test were performed, respectively at the age of 7, 14, 21, and 28 days. The results showed that the increase in use of a foaming agent will cause a reduction in the density and the compressive strength of the concrete. While the porosity of foam concrete which is measured at the "volume of permeable void" will increase with the decreasing density and compressive strength of concrete.