中文摘要：

基于断裂力学理论,采用单边带裂缝梁三点弯曲试验,研究了沥灰比（沥青/水泥质量比mA/mC）对水泥乳化沥青（CA）砂浆断裂行为的影响。根据测试的荷载–扰度（P–d）和荷载–裂缝口张开位移（P–dc）曲线,计算了不同沥灰比CA砂浆的应力强度因子KI、J积分和断裂能,并测试了CA砂浆的抗压及抗折强度。结果表明：随着沥灰比的增大,CA砂浆的强度降低但变形能力（延性）增大,CA砂浆由准脆性断裂过渡为韧性断裂;当mA/mC〈0.5时,CA砂浆呈准脆性断裂,可用由线弹性断裂力学导出的断裂韧度K（Ic）表征其断裂韧性;少量沥青的掺入虽使CA砂浆裂缝尖端塑性变大,但亦导致其强度降低,因而沥灰比为0.3时CA砂浆的K（Ic）=0.248 5 MPa×m^（1/2）,约为水泥砂浆的一半;当mA/mC≥0.5时,CA砂浆因塑性较大而呈韧性断裂,应用弹塑性断裂力学导出的J（Ic）表征其韧性;沥灰比由0.5增大到0.9时,CA砂浆的JIc由39.222变为34.848 J/m^2,且因延性增大而使其断裂能由31.97增加到46.37 N/m;沥青相主要通过增大CA砂浆的延性而提高其韧性。

英文摘要：

Based on the theory of fracture mechanics, the fracture behavior of emulsified asphalt cement （CA） mortar with different asphalt to cement mass ratios （mA/mc） were investigated. Their stress intensity factor, J integral and fracture energy were calculated based on the load-bending deflection and load-crack mouth open displacement curves obtained from the three-point bending test, respectively. Their compressive and bending strengths were also measured. The results show that both the strength and fracture performance of CA mortar are closely related to the mA/mc. With the increase ofmA/mc, the strength of CA mortar decreases and the deformability （ductility） increases, thus, the fracture mode of CA mortar experiences a transition from quasi-brittle fracture to ductile fracture with the increase of mA/mc. CA mortars with mA/mc〈0.5 exhibit a quasi-brittle fracture behavior, and whose fracture toughness can be characterized by fracture toughness KIC value deduced from the theory of linear elastic fracture mechanics. The addition of a small amount asphalt in cement mortar leads to the ductility increase slightly but the strength of CA mortar decrease greatly, hence, the KIC value of CA mortar with mA/mc=0.3 is 0.248 5 MPa.m1/2, that is about a half of Kie value of the cement mortar without asphalt. On the other hand, CA mortars with rnA/mc≥0.5 exhibit a ductile fracture behavior due to the higher ductility, and whose fracture toughness should be characterized by Jic value deduced from the theory of elastic-plastic fracture mechanics. As the mA/mc increases from 0.5 to 0.9, the JIC value of CA mortar is slightly lowered from 39.222 to 34.848 J/m2, however, the fracture energy is enhanced from 31.97 to 46.37 N/m. It is considered that the asphalt phase improves the toughness of CA mortar mainly by increasing its ductility.