Physical and Mechanical Properties of Crumb Rubber Mortar(CRM)with Interfacial Modifiers

Eight interfacial modifiers were used to improve the interfacial bonding strength between the crumb rubber and matrix of Crumb Rubber Mortar （CRM）, and the physical and mechanical properties and microstructure of CRM were also studied. The results show that, the interfacial modifiers obviously improve the interface bonding strength between the crumb rubber and matrix and the whole strength of CRM, and silicone modified styrene-acryl ate-emulsion has the best effect. The rubber-cement matrix interface was proved by SEM that the interfacial modifiers treated rubber showed good adhesion to the matrix.

Static compressive properties and damage constitutive model of rubber cement mortar with dry-and wet-curing conditions

To investigate the static compressive properties and mechanical damage evolution of rubber cement-based materials(RCBMs) with dry-and wet-curing conditions, uniaxial compression and cyclic loading-unloading tests were carried out on rubber cement mortar(RCM). The mechanical properties of the uniaxial compression specimens cured at 95%(wet-curing) and 50%(dry-curing) relative humidities and cyclic loading-unloading specimens cured at wet-curing were analyzed. Under uniaxial compression, the peak stress loss ratio is higher for dry-curing than for wet-curing. The peak strain decreases with the increase of rubber content, and the peak strain increases with the decrease of curing humidity. Under cyclic loading-unloading, the variation trends of residual strain differences of the normal cement mortar and RCM at each cyclic level with the number of cycles are basically the same, but the failure modes are different. The analysis of the internal mesostructure by a scanning electron microscope(SEM) shows that initial damage is further enhanced by reducing curing humidity and adding rubber aggregate. The damage constitutive model based on strain equivalence principle and statistical theories was used to describe the uniaxial compression characteristics of RCM, and the law of mechanical damage evolution was predicted.