Self-sealing cementitious materials by utilizing superabsorbent polymers

A current direction in scientific research is the search for technological solutions that provide high reliability for building materials. Incorporating self-sealing agents during the design phase makes concrete more eco-friendly by reducing the maintenance processes and extending concrete's lifespan which leads to reducing the need to produce cement causing a lot of CO2 emissions. As a consequence, this investigation describes an attempt to assess the performance of superabsorbent polymer (SAP) as a self-sealing agent. In the experimental work, two different particle sizes were taken into consideration, SAP1 (425–600μm) and SAP2 (> 600 μm) and for preparing SAP-based concrete and the ratio of SAP was (0.3% wt of cement) with water/ cement (0.4). The regular test was performed for compressive strength at the age of 28 days and the pre-crack phase to generate the initial crack started after 28 days. Two series of sealing periods Cy4th and Cy10th under wet-dry cycles were taken to promote the sealing process. The DZM (Digital Zoom Microscope) system for microscopic analysis was used to detect the self-sealing phenomenon and the width of the sealing on the concrete cracks' surface by using specialist software (image process). The outcomes demonstrated that there was a positive effect of using SAP as a sealing agent, depending on particle size the SAP2 healed the crack up to 0.15mm and the percentage of partially sealing at Cy4th was 64% compared to the other mixes.