玄武岩纤维和水化硅酸钙协同增强混凝土力学性能研究

Study on the Mechanical Properties of Concrete Reinforced by Basalt Fiber and Hydrated Calcium Silicate

玄武岩纤维(BF)和水化硅酸钙(CSH)晶核早强剂,分别在提升混凝土的韧性和抗压强度方面具有突出的作用。为了研究二者共同作用下混凝土力学性能的变化规律,选用6 mm和18 mm的BF与CSH按不同质量比例掺入混凝土中。对试件的抗压强度、劈裂抗拉强度和抗折强度进行测试,并对水化产物进行了表征。研究表明:混掺BF和CSH晶核早强剂能有效提升混凝土的力学性能,且18 mm的BF对混凝土力学性能的增强作用优于6 mm;当18 mm的BF与CSH比例为0.10∶0.45时,抗压强度比对照组提高了9.1%;当二者的比例为0.05∶0.45时,劈裂抗拉强度和抗折强度分别比对照组提高了24.1%、18.3%;XRD和SEM测试发现,CSH能诱导生成更多的水化硅酸钙和钙矾石,使体系结构更加致密,从而提高混凝土的力学性能。

Basalt fiber(BF)and hydrated calcium silicate(CSH)crystal core early strengthening agents,respectively,have a prominent role in improving the toughness and compressive strength of concrete.In order to study the change rule of the mechanical properties of concrete under the combined action of the two, BF and CSH of 6 mm and 18 mm were selected to be mixed into concrete at different mass ratios. The compressive strength, split tensile strength and flexural strength of the specimens were investigated, and the hydration products were characterized. The results show that mixing BF and CSH crystal core early strengthening agent can effectively improve the mechanical properties of concrete, and the enhancement effect of 18 mm BF on the mechanical properties of concrete is better than that of 6 mm. When the ratio of BF to CSH of 18 mm was 0. 10 ∶0. 45, the compressive strength increased by 9. 1% compared with the control group. When the ratio of the two was 0. 05∶0. 45, the split tensile strength and fracture strength increased by 24. 1% and 18. 3%, respectively, compared with the control group. XRD and SEM tests show that CSH can induce the formation of more hydrated calcium silicate and ettringite, which makes the system structure more compact and thus improves the mechanical properties of concrete.