Zhang Yingda, Li Haiyang, Zhang Haojie, Zhou Xianliang, Xu Ziyi, Liu Zihao
School of Architecture and Civil Engineering, Xihua University, Chengdu 610039, China.
Sichuan Provincial No. 12 Geological Team, Yibin 644002, China.
Materials (Basel). 2025 Aug 11;18(16):3757. doi: 10.3390/ma18163757.
The mitigation of early-age shrinkage and thermal cracking remains a pressing challenge in mass concrete structures. This study introduces a novel temperature-control admixture (TCA), formulated with gel-forming inorganic compounds, designed to suppress internal temperature rise while improving the mechanical stability of fly ash concrete. Four concrete mixes with TCA dosages of 0, 0.05, 0.10, and 0.15% were experimentally evaluated under controlled environmental conditions. Results show that the optimal dosage of 0.10% achieved a 27.3% reduction in shrinkage and a 12.2% increase in compressive strength at 28 days compared to the control. Furthermore, existing shrinkage models (Eurocode 2, fib Model Code 2010, AS 3600, Bazant B4) consistently overestimated shrinkage by up to 294% due to their inability to capture TCA-induced modifications in hydration and moisture transport. To address this, a modified prediction model incorporating admixture and fly ash-dependent correction factors was proposed, reducing the mean prediction error to just 10% and achieving a coefficient of variation as low as 0.08. This work provides a semi-empirical modeling approach that captures the influence of microencapsulated TCAs on concrete shrinkage and offers useful insights for the design and optimization of advanced concrete systems.
在大体积混凝土结构中，减轻早期收缩和温度裂缝仍然是一个紧迫的挑战。本研究引入了一种新型温控外加剂（TCA），它由凝胶形成无机化合物配制而成，旨在抑制内部温度上升，同时提高粉煤灰混凝土的力学稳定性。在可控环境条件下，对四种TCA掺量分别为0%、0.05%、0.10%和0.15%的混凝土配合比进行了实验评估。结果表明，0.10%的最佳掺量与对照组相比，28天时收缩率降低了27.3%，抗压强度提高了12.2%。此外，现有的收缩模型（欧洲规范2、fib 2010模型规范、澳大利亚标准3600、巴赞特B4）由于无法捕捉TCA引起的水化和水分传输变化，一直高估收缩率高达294%。为了解决这个问题，提出了一个包含外加剂和粉煤灰相关修正系数的改进预测模型，将平均预测误差降低到仅10%，变异系数低至0.08。这项工作提供了一种半经验建模方法，该方法捕捉了微胶囊化TCA对混凝土收缩的影响，并为先进混凝土系统的设计和优化提供了有用的见解。
