Zhang Yingda, Zhang Junru, Chen Jun, Yan Zhijian, Liu Xinyue, Zhang Haojie
Key Laboratory of Transportation Tunnel Engineering, Ministry of Education, School of Civil Engineering, Southwest Jiaotong University, Chengdu 610031, China.
School of Architecture and Civil Engineering, Xihua University, Chengdu 610039, China.
Materials (Basel). 2025 Mar 10;18(6):1230. doi: 10.3390/ma18061230.
This study investigates the effect of microencapsulated temperature rise inhibitors (TRIs) on the hydration temperature evolution and crack resistance of medium-sized concrete structures. Unlike mass concrete, medium-sized concrete elements such as beams, slabs, and columns pose unique challenges in temperature control due to their moderate volume, limited heat dissipation, and susceptibility to thermal stress-induced cracking. To address this issue, concrete mixtures with TRI dosages of 0%, 0.05%, 0.1%, and 0.15% were evaluated using a sealed foam box method, allowing for precise monitoring of hydration temperature development under insulated conditions. The results indicate that TRIs effectively suppress peak hydration temperature and delays its occurrence, with higher TRI dosages leading to more pronounced effects. X-ray diffraction (XRD) and scanning electron microscopy (SEM) analyses confirm that the hydration suppression is attributed to a controlled-release mechanism, where TRIs gradually dissolve, forming a hydration barrier on cement particles. This slows down calcium hydroxide (CH) crystallization, alters C-S-H gel evolution, and reduces early age heat accumulation, mitigating thermal cracking risks. Furthermore, mechanical property tests reveal that, while early age compressive and tensile strength decrease with TRI addition, long-term strength recovery is achieved at optimum TRI dosages. This study identifies 0.1% TRI as the most effective dosage, striking a balance between hydration heat reduction and long-term mechanical performance. These findings provide a scientific basis for optimizing TRI dosages in medium-sized concrete applications, offering a practical solution for thermal cracking prevention.
本研究调查了微胶囊化温升抑制剂（TRIs）对中型混凝土结构水化温度演变及抗裂性的影响。与大体积混凝土不同，梁、板、柱等中型混凝土构件因其体积适中、散热有限且易受温度应力诱导开裂的影响，在温度控制方面面临独特挑战。为解决这一问题，采用密封泡沫箱法对TRI剂量分别为0%、0.05%、0.1%和0.15%的混凝土混合物进行了评估，从而能够在隔热条件下精确监测水化温度的发展。结果表明，TRIs能有效抑制水化温度峰值并延迟其出现，TRI剂量越高，效果越显著。X射线衍射（XRD）和扫描电子显微镜（SEM）分析证实，水化抑制归因于控释机制，即TRIs逐渐溶解，在水泥颗粒上形成水化屏障。这减缓了氢氧化钙（CH）的结晶，改变了C-S-H凝胶的演变，并减少了早期热量积累，降低了热裂风险。此外，力学性能测试表明，虽然添加TRI会使早期抗压和抗拉强度降低，但在最佳TRI剂量下可实现长期强度恢复。本研究确定0.1%的TRI为最有效剂量，在降低水化热和长期力学性能之间取得了平衡。这些发现为中型混凝土应用中优化TRI剂量提供了科学依据，为预防热裂提供了切实可行的解决方案。
