Research on strength and microstructure of fibre foamed concrete

Foamed concrete is a porous cement-based material composed of cement, foaming agent, and water. It has the advantages of light weight, good integrity, and convenient construction. It is widely used in construction engineering, subgrade engineering, and backfilling of bridge abutments. Due to the shrinkage cement and load, the foamed concrete cracks, which affects the performance. In order to improve the crack resistance of the foamed concrete, this study added basalt fibre, glass fibre, polyester and wood fibre to the foamed concrete, and tested its mechanical properties and microstructure. The results show that the addition of basalt fibre, glass fibre, and polyester can improve the compressive strength and flexural strength of foamed concrete. Among them, glass fibre foamed lightweight soil has higher flexural strength, and polyester foamed concrete has higher compressive strength. The strength of polyester foamed concrete increases with the increase of fibre addition, and the strength of glass fibre foamed concrete will decrease when the adding amount of glass fibre exceeds 0.1%. According to industrial CT (Computed Tomography) test results, the average void volume and the number of voids will decrease after adding fibres.