Effects of re-dispersible latex powder-basalt fibers on the properties and pore structure of lightweight foamed concrete

In order to diminish global energy consumption and environmental pollution, the use of green building materials for construction has been noticeably popularized. In the present study, the use of re-dispersible latex powder-basalt fibers to prepare foamed concrete to improve the performance of foamed concrete has been assessed. The effects of basalt fibers and re-dispersible latex powder on the dry and wet densities, water adsorption rate, compressive strength, and microstructure of the foamed concrete, were then studied. The hydration products and pore structure were analyzed by X-ray diffraction (XRD) spectroscopy and scanning electron microscopy (SEM). The results revealed that basalt fibers slightly affected the density and water adsorption rate. With the increase in the content of re-dispersible latex powder, the wet density of the specimen increased, the dry density decreased, the difference between dry density and wet density increased, and the water adsorption rate decreased. With the addition of a re-dispersible latex powder, the pore size decreased, the pore structure density increased, and the effective pore number was elevated. Furthermore, the compressive strength of double-doped re-dispersible latex powder-basalt fibers was higher than that of single-doped basalt fibers. The XRD analysis of the hydration products and the SEM analysis of the microstructures confirmed that the re-dispersible latex powder formed new hydration products after hydration. These hydration products gathered on the foam surface and became fused to form a film. Also, the polymer membrane interweaves with the hydration products to form a continuous network. The basalt fibers were evenly distributed in the internal structure, penetrated the polymer membrane, and formed a three-dimensional random network system. The random network system could support the bubbles and had the effect of secondary reinforcement. Moreover, the interfacial adhesive force between the fibers and the polymer film dispersed a part of the energy and produced a more continuous and uniform stress field in the structure.