Experimental and numerical explorations on the optimized applications of SCDA in cracking concrete blocks

Abstract

For effective applications of a soundless chemical demolition agent (SCDA) in fragmenting concrete blocks, experimental and numerical investigations were conducted. Firstly, the maximum expansion pressures under varying water/SCDA ratio, water temperature, and hole diameter were determined via experimental tests. Then, cracking experiments were performed on lab-scale concrete blocks with two predrilled holes by using strain gouge and acoustic emission tool. It was observed hole diameter exerts a primary control on the cracking process. The cracking process is generally divided into three stages, named micro-cracking stage, macro-cracking stage, and failure stage. Furthermore, two-dimensional realistic failure process analysis (RFPA2D) code was applied to reproduce the failure process of laboratory concrete blocks. The verified model was employed to simulate the cracking process of meter-scale concrete specimens with multi-holes of staggered and square arrangements. Empirical equations were formulated to correlate the cracking area with the hole diameter, spacing, and tensile strengths of concrete.