A computational model for thick concrete slab demolition using soundless chemical demolition agent

Soundless chemical demolition agents (SCDAs) provide a feasible route to meet the demolition in the modern construction industry. Exploration of how to efficiently demolish reinforced concrete members with SCDAs is in deep demand. To investigate the method and computational model of demolishing thick concrete slab, static crushing experiments of 12 thick concrete slab specimens with different parameters were carried out. To remove the constraint of reinforcements, the reinforcements in the upper part of the thick concrete slab specimens were cut off along the hole connection and its extension line before grouting. The results showed that cracks were formed at the cutting seams on the upper surface due to the defect caused by cutting reinforcements, and these cracks extended to the bottom of the specimens. The development of cut seam width was over 80% on the first day, and 20% in the following day. Besides, the ratio of the area of the cut seams on the upper surface of the specimen to the area of the upper surface of the specimen (i.e. crack area ratio) was proposed to evaluate the influence of the compressive strength of concrete, hole spacing, and hole diameter in the concrete demolition. Finally, a new computational model for calculating hole spacing by taking time, compressive strength of concrete, hole diameter, ambient temperature, and crack area ratio into consideration was proposed. The proposed computational model was verified with experimental data and was expected to guide the application of SCDAs in civil engineering.