Experimental study of dynamic behavior of cement-based composites

Abstract

Fabric-reinforced cement-based composites are a new class of sustainable construction materials with superior tensile strength and ductility. They demonstrate a significant improvement in the energy absorption capacity as compared to plain concrete materials and fiber-reinforced composites. Due to the inherent brittleness and low tensile strength of most cement-based elements, dynamic loading can cause severe damage and cracking. In order to accurately analyze and design structures that are subjected to dynamic loading, it is necessary to utilize the mechanical properties associated with the strain rates to which the structural components are subjected. In this work, we studied the dynamic behavior of cement composites reinforced with 2D Alkali Resistant (AR) glass and polyethylene fabrics under high-speed tensile loading and composites reinforced with 3D AR glass fabric and short AR glass fiber under impact loading in 3-point bending. The dynamic material properties, including Young’s modulus, tensile strength, toughness, and maximum strain are obtained. Typical stress–strain curves representing the tensile behavior of individual composites were compared. The differences in tensile behavior of the composites were correlated with the different structure and mechanical properties of the fabrics. A multiple cracking behavior was observed for 2D fabric–cement composites, indicating good stress transfer within composites. The impact response of 3D fabric–cement composite was studied and compared to that of short AR glass fiber composite with same cement matrix. We found that the 3D fabric can significantly improve the toughness of cement-based composites as much as 200 times higher than the short fiber. These results can provide tools to design composites that might be subjected to extreme loading conditions during their service life.