纤维增强泡沫混凝土的力学强度及吸水性能

以普通硅酸盐水泥和动物蛋白发泡剂为基材，制备了泡沫混凝土，研究了：试样强度随水灰比、干密度、纤维长度、纤维类型的变化规律；单轴受压下应力应变全曲线；试样微观泡孔分布以及吸水性能的变化。结果表明，素泡沫混凝土和纤维增强泡沫混凝土的抗压强度均随孔隙率增加呈指数减小，水灰比对抗压强度的影响随纤维添加量、孔隙率的不同而不同。短丝纤维对强度的提升优于长丝纤维，网状纤维对强度的改善优于丝状纤维；纤维泡沫混凝土应力应变全曲线包括上升、下降和峰后三段，与素泡沫混凝土相比，其峰值应力对应的峰值应变减小，而弹性模量和残余应力均大幅增加；大直径泡孔占比随纤维添加量增加而降低，添加纤维提升了试样的吸水性能。

Mechanical strength and water absorption capability of fiber-reinforced foamed concrete

The foamed concrete (FC) was produced by using the main materials including Portland cement and foaming agent of animal protein. The effects of water-cement ratio, dry density, fiber lengths and fiber types on strengths, complete stress-strain curves under uniaxial compression, distributions of pore size and water absorption capability were investigated. Test results indicate that the compressive strength decreases exponentially with increasing porosity for both FC and fiber-reinforced foamed concrete (FRFC). The compressive strength has its different changing patterns with water-cement ratio for different fiber contents and porosities. In addition, the compressive and tensile strengths can be apparently raised by shorter fiber filament and change variously with different fiber contents. A greater improvement of compressive and tensile strengths is obtained by adding fiber meshes compared with fiber filaments under the same conditions. Three segments are discovered in the complete stress-strain curve, which include ascend, decend and fluctuant processes. The peak strain of FRFC reduces, however, the modulus of elasticity and residual strength of FRFC increases. For FRFC, the percentage of pore with larger radius decreases with increasing fiber content. Thus, the water absorption capability can be enhanced by fiber.