Effect of Phenolic Particles on Mechanical and Thermal Conductivity of Foamed Sulphoaluminate Cement-Based Materials.

Xiuzhi Zhang,Qinfei Li,Xin Cheng,Qing Yang,Heng Chen,Guofa Zheng

doi:10.3390/ma12213596

Abstract

Foamed concrete materials based on sulpoaluminate cement were prepared by the chemical foaming method. The effects of water–cement ratio, foaming agent, and foaming stabilizer on the mechanical and thermal properties of foamed concrete were studied. Meanwhile, a portion of cement was replaced with foamed phenolic particles to further optimize the performance of foamed concrete; the results show that when the water–cement ratio was 0.53, the foaming agent content was 5%, the foam stabilizer was 1%, and the substitution of phenolic particles was 20%, the performance indexes of foamed concrete were the best. Methods, describing briefly the main methods or treatments applied: dry density was 278.4 kg/m3, water absorption was 19.9%, compressive strength was 3.01 MPa, and thermal conductivity was 0.072 W/(m·K). By the pore structure analysis of the foamed concrete suing Micro-CT, it was found that when the replacement amount of phenolic particles was 20%, the pore size of foamed concrete was relatively uniform, the minimum D90 was 225 μm respectively. The combination of organic and inorganic matrix and optimized pore structure improved the performance of foamed concrete.

Highlights

As a cement based thermal insulation material, foamed concrete is more attractive than polymer foam materials for its unique set of properties: it has high heat capacity, excellent fire resistance, and low cost [1,2,3,4,5,6]
The average dry density of six specimens with the same mix proportion was chosen as the dry density of theoffoamed concrete
The performance of foamed concrete was significantly determined by the water to cement ratio, which can influence the fluidity behavior and pore structures of foamed composites, is able to affect its mechanical strength property and thermal conductivity value

Summary

Introduction

As a cement based thermal insulation material, foamed concrete is more attractive than polymer foam materials for its unique set of properties: it has high heat capacity, excellent fire resistance, and low cost [1,2,3,4,5,6]. Most research efforts to foamed cementitious materials have focused on ordinary Portland cement, which has a slow hydration speed at normal conditions and a slow growth rate. Foamed concrete can be demoulded after 24 h under the condition of adding accelerator [7,8,9,10]. Compared with organic thermal insulation materials, the thermal conductivity of conventional cement-based foam materials is higher. The researchers found that the thermal conductivity of organic–inorganic lightweight composite materials can be significantly reduced by using organic foam particles as lightweight aggregates [12,13], the lower thermal conductivity of 0.0848 W/(m·K) was Materials 2019, 12, 3596; doi:10.3390/ma12213596 www.mdpi.com/journal/materials

Methods

Results

Conclusion