Mechanical, thermal insulation, thermal resistance and acoustic absorption properties of geopolymer foam concrete

Abstract

This study reports the synthesis and characterization of geopolymer foam concrete (GFC). A Class F fly ash with partial slag substitution was used for GFC synthesis by mechanical mixing of preformed foam. The GFCs exhibited 28 day compressive strengths ranging from 3 to 48 MPa with demolded densities from 720 to 1600 kg/m 3 (105°C oven-dried densities from 585 to 1370 kg/m 3 ), with the different densities achieved through alteration of the foam content.The thermal conductivity of GFCs was in the range 0.15 to 0.48 W/m·K, showing better thermal insulation properties than normal Portland cement foam concrete at the same density and/or at the same strength. The GFC derived from alkali activation of fly ash as a sole precursor showed excellent strength retention after heating to temperatures from 100 to 800°C, and the post-cooling compressive strength increased by as much as 100% after exposure at 800°C due to densification and phase transformations. Partial substitution of slag for fly ash increased the strength of GFC at room temperature, but led to notable shrinkage and strength Preprint of: Z Zhang, JL Provis, A Reid, H Wang, Mechanical, thermal insulation, thermal resistance and acoustic absorption properties of geopolymer foam concrete (GFC), Cement and Concrete Composites, 62(2015): 97-105. Final published version is at: http://dx.doi.org/10.1016/j.cemconcomp.2015.03.013 2 loss at high temperature. Thin GFC panels (20 -25 mm) exhibited acoustic absorption coefficients of 0.7-1.0 at 40 to 150 Hz, and 0.1-0.3 at 800 to 1600 Hz.

Alkali-activated materials

“…A wide variety of routes to foamed alkali-activated materials have also been demonstrated [85][86][87][88][89][90][91], and these offer pathways to the reduction of operational energy.…”

Manufacturing of Fire Resistance Geopolymer: A Review

“…The temperature on the cold side of the panels was 350°C after exposure up to 1100°C for 35 min [10]. Others, Zhang et al [9] found that geopolymer derived from alkali activation showed excellent strength retention after heating to temperature from 100 to 800°C, and the postcooling compressive strength increased by as much as 100% after exposure 800°C due to densification and phase transformation as shown in Figure 1. This paper review demonstrate that geopolymer composites are promising fire resistance material for engineering applications.…”

“…Geopolymer has been proposed for very good heat resistance having thermal stability up to 800 -1200°C [9]. Nevertheless, it is reported that geopolymers panels made of granulated slag filler and metakaolin exhibited an improved fire resistance behavior.…”

Utilization of Foaming Technology in Cemented Paste Backfill of High-Mud Superfine Unclassified Tailings

“…A foaming agent, which is a surfactant, can effectively reduce the surface tension of a liquid and form bubbles with the surrounding air with its double-electron layer arrangement in the liquid film surface [11]. Hydrophilic, carboxyl, and hydrophobic are the main molecular composition of LC-01 foaming agent after being uniformly diluted.…”