喷涂聚脲纤维混凝土劈裂抗拉性能试验研究

Experimental study on splitting tensile properties of sprayed polyurea fiber reinforced concrete

为研究聚脲对纤维混凝土劈裂抗拉性能的影响,应用数字图像相关方法(DIC)和超声波检测技术,对喷涂聚脲纤维混凝土劈裂抗拉过程中的应变和波速信息进行分析,得到不同加载阶段应变场和波速场的变化特征。结果表明:喷涂聚脲纤维混凝土的劈裂抗拉强度随着聚脲厚度的增加而增加,当聚脲厚度为7 mm、纤维掺量为0.3%时,劈裂抗拉强度达到4.31 MPa,是同一纤维掺量混凝土的1.19倍;喷涂聚脲可以提高纤维混凝土的韧性,延缓损伤产生;DIC和超声波检测技术在表征混凝土损伤方面具有内外关联性,可更全面的反映混凝土的损伤过程。

In order to study the effect of polyurea on the splitting tensile properties of fiber reinforced concrete,the digital image correlation method(DIC)and ultrasonic detection technology were used to analyze the strain and wave velocity information in the splitting tensile process of sprayed polyurea fiber reinforced concrete.Through analysis,the variation characteristics of strain field and wave velocity field in different loading stages are obtained.The results show that the splitting tensile strength of spray polyurea fiber reinforced concrete increases with the increase of polyurea thickness.When the fiber content is 0.3%and the polyurea thickness is 7 mm,the splitting tensile strength reaches 4.31 MPa,which is 1.19 times that of concrete with the same fiber content.Spraying polyurea can improve the toughness of fiber reinforced concrete and delay damage.DIC and ultrasonic detection technology have internal and external correlations in characterizing concrete damage,which can more comprehensively reflect the damage process of concrete.