Najaf Erfan, Orouji Maedeh, Li Linfei, Landis Eric N
Department of Civil and Environmental Engineering, University of Maine, Orono, ME 04469, USA.
Department of Civil and Environmental Engineering, Florida International University, Miami, FL 33174, USA.
Materials (Basel). 2025 May 9;18(10):2194. doi: 10.3390/ma18102194.
The durability of concrete is compromised by early-age cracking, which provides a pathway for harmful ions and water to penetrate the material. Early-age cracking, however, is most commonly caused by concrete shrinkage. This study investigates strategies for minimizing the shrinkage of concrete by optimizing aggregate gradation via the Tarantula Curve, reducing cement content, and incorporating lightweight fine aggregates (LWFA) as internal curing agents. The commercially adopted mix design was used as a reference, with the cementitious materials-to-aggregate (C/A) ratio reduced from 0.21 (reference) to 0.15 (proposed), incorporating 0-15% LWFA replacement levels. Workability (ASTM C143), mechanical performance (ASTM C39, ASTM C78), durability (AASHTO TP 119-21), and dimensional stability (ASTM C157) were evaluated through ASTM standard tests. The results highlight that optimizing the C/A ratio cannot only improve both compressive and flexural strengths in regular concrete but also mitigate the total shrinkage by 12.68%. The introduction of LWFA further reduced shrinkage, achieving a 19.72% shrinkage reduction compared to regular concrete. In addition, the sustainability of the developed mix designs is enhanced by the reduced cement usage. A Life Cycle Assessment (LCA) based on the TRACI method confirmed the sustainability advantages of cement reduction. The optimized mix designs resulted in a 30% decrease in CO emissions, emphasizing the role of mix design in developing environmentally responsible concrete. Overall, lowering the cement amount and the addition of LWFA provide an optimal combination of shrinkage control, strength retention, and sustainability for applications.
混凝土的耐久性会因早期开裂而受损，早期开裂为有害离子和水渗透到材料中提供了途径。然而，早期开裂最常见的原因是混凝土收缩。本研究探讨了通过采用狼蛛曲线优化骨料级配、减少水泥用量以及掺入轻质细骨料（LWFA）作为内部养护剂来最小化混凝土收缩的策略。以商业采用的配合比设计作为参考，将胶凝材料与骨料（C/A）的比例从0.21（参考值）降低到0.15（建议值），同时掺入0 - 15%的LWFA替代量。通过ASTM标准试验评估了工作性（ASTM C143）、力学性能（ASTM C39、ASTM C78）、耐久性（AASHTO TP 119 - 21）和尺寸稳定性（ASTM C157）。结果表明，优化C/A比例不仅能提高普通混凝土的抗压强度和抗弯强度，还能使总收缩率降低12.68%。引入LWFA进一步减少了收缩，与普通混凝土相比，收缩率降低了19.72%。此外，减少水泥用量提高了所开发配合比设计的可持续性。基于TRACI方法的生命周期评估（LCA）证实了减少水泥用量在可持续性方面的优势。优化后的配合比设计使二氧化碳排放量减少了30%，强调了配合比设计在开发对环境负责的混凝土中的作用。总体而言，降低水泥用量和添加LWFA为应用提供了收缩控制、强度保持和可持续性的最佳组合。
