Rania Ihsan Ali Al-Nawasir

This study aims to create sustainable cement grout for semi-flexible pavement applications that can withstand high traffic and severe weather conditions. Portland cement was partially replaced by CWP in varying percentages (15%, 20%, 30%, 40%, and 50%) to produce cement-based grout. The grout mixtures were tested for compressive strength and flow properties. A life cycle assessment (LCA) was also conducted to evaluate the sustainability performance of both conventional and modified grout with CWP. The mechanical test results showed that the optimal cement replacement ratio with CWP is 20%, which increased the compressive strength, skis resistance, indirect tensile strength, and tensile strength ratio by 50%, 25%, 64%, and 24%, respectively, at 28 days of curing. Similarly, the durability test results indicated that incorporating the same CWP content at the same curing age reduced particle loss and rutting by 31% and 76%, respectively. This significant improvement in performance tests can be attributed to the high flowability of CWP, which fills all voids in the porous asphalt mixture, and its superior ability to produce a significant amount of calcium silicate hydrate (C–S–H) gel. According to the LCA results, increasing CWP cement replacement levels resulted in lower environmental impacts and improved sustainability performance for the developed grouts.

Semi-flexible pavement (SFP), also known as grouted pavement, is a type of pavement structure consisting of a porous asphalt skeleton with air voids between 25 and 35% injected with cementitious grout materials. The special skeleton of SFP provided enhanced durability and resilience, making it a promising option for the construction of road surfaces in high-traffic areas and severe conditions. The main aim of the current research is to investigate the rutting behavior and moisture resilience of SFP-containing sustainable grout using ceramic waste powder (CWP). This research introduced the use of CWP as a replacement for conventional grout (cement) in SFP for the first time. CWP partially replaced cement at ratios of 15, 20, 30, 40, and 50% of the cement weight. Indirect Tensile Strength (ITS) and Hamburg Wheel Tracking Tests (HWTT) were used to evaluate the performance of SFP to reduce the detrimental effect of moisture. The grout modified with CWP shows excellent results in the ITS and Tensile Strength Ratio (TSR), and all modified SFP mixtures give higher values in these tests compared with Control Mix (CM). In the HWTT, the minimum rut depth of the modified SFP was 2.8 mm and 3.10 mm. Compared to CM, rutting decreased by 73%–76% for CWP mixes with 20% and 30% replacement. This indicates the high fluidity of CWP, which enabled it to penetrate all voids in the porous pavement (PA) and form a dense microstructure due to its excellent pozzolanic interaction, making it a strong structure capable of bearing rutting.