Preparation and characterization of a fly ash and cement-based foam composite

Abstract

Industrial waste fly ash and ordinary Portland cement (PO42.5) were used as the main raw materials, Ca(OH)2 as the alkali activator, modified rosin soap as the foaming agent, and glass fiber as the reinforcing agent. A physical foaming technology was chosen to fabricate a fly ash and cement-based foam composite. The effects of water-to-binder (W/B) ratio and glass fiber addition on the performance of the foam composite were studied. The structure formation and reinforcement mechanism of the foam composite were discussed, and the optimal formulation was determined, which provides a new technical approach to utilize fly ash and improve the strength and reliability of foam cement products. The results show that different water-to-binder ratios directly affect the stability of the pores during the foaming process, and the glass fiber has a protective effect on the foam. When the W/B ratio is 0.5, meanwhile the addition of glass fiber is 1.5%, the fly ash and cement-based foam composite can achieve better physical performance: the dry density is 368 kg/m3, the water absorption rate is 39.12%, and the 28-day compressive strength is increased by 86.31% (reaching 3.47 MPa) compared to that of the sample without a glass fiber.