Portland Limestone Cement for durable low carbon infrastructure concrete

Portland Limestone Cement (PLC), designated as Type IL under ASTM C595/C595M and Type GUL under CSA A3001, is now a mainstream clinker-reduction strategy for concrete infrastructure. Because the performance of commercial PLC containing up to 15% limestone is already well established, the principal question is no longer whether such cements can replace Ordinary Portland Cement (OPC) under routine conditions, but how durability specifications, higher-limestone formulations, and multicomponent systems should evolve without sacrificing service life. This critical narrative review synthesizes more than 100 peer-reviewed, technical, and standards sources across six geographic regions. The 5–15% Type IL/GUL range is treated as the commercial baseline, while higher-limestone systems, including CEM II/B-L cements containing 21–35% limestone and low-clinker ternary or composite cements, are evaluated as an emerging performance domain. The review integrates four themes that are rarely considered together in PLC-focused syntheses: durability-conditioned equivalence with OPC, global specification and code development, interactions with supplementary cementitious materials (SCMs), and limestone-quality variability. Commercial PLC generally provides comparable mechanical, chloride, and freeze-thaw performance when water-to-cementitious materials ratio, curing, and air entrainment are appropriately controlled. Carbonation and sulfate resistance remain the durability characteristics most sensitive to clinker dilution and clinker C 3 A content, respectively. Evidence for limestone contents above 15% demonstrates technically viable low-clinker concrete, particularly when limestone is combined with reactive SCMs, but the evidence base is more heterogeneous and long-term field validation remains limited. The standards synthesis further shows that European frameworks accommodate higher limestone contents and multicomponent cements more explicitly than current North American practice. The review therefore identifies performance-based durability qualification, long-term field data for higher-limestone systems, and validated rapid test methods for multicomponent binders as priority needs for the next generation of PLC specifications.