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- 混凝土与制品
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膨胀混凝土早龄期变形及力学性能试验研究
作者：汪洋1，王育江1，2，李华1，2
（1.江苏苏博特新材料股份有限公司，高性能土木工程材料国家重点实验室，江苏 南京 211103；
2.东南大学 材料科学与工程学院，江苏 南京 211189）
摘要：研究了膨胀剂和矿物掺合料对混凝土早龄期变形及力学性能的影响。结果表明，掺入膨胀剂后膨胀混凝土的早龄期抗压强度提高了6%~17%，早龄期劈裂抗拉强度降低了27%~42%，但对混凝土28 d龄期时的力学性能影响很小。混凝土早龄期弹性模量在掺入膨胀剂后普遍有下降的趋势，至28 d龄期，膨胀混凝土的动弹性模量降低了1.5~7.3 GPa。膨胀混凝土由于膨胀剂的效能，可在早龄期存储较大的膨胀变形以补偿混凝土收缩，早龄期膨胀混凝土的最大膨胀变形可达到142 με~315 με，有利于结构混凝土抗裂性能的提升。但在膨胀混凝土中掺入矿粉会显著增大混凝土的自收缩，使膨胀剂的膨胀组分作用减弱。
关键词：早龄期；膨胀混凝土；变形；力学性能
中图分类号：TU528.55 文献标识码：A 文章编号：1001-702X（2022）06-0086-05
Experimental study on deformation and mechanical properties of expansive concrete at early-age
WANG Yang1，WANG Yujiang1，2，LI Hua1，2
（1.State Key Laboratory of High Performance Civil Engineering Materials，Jiangsu Sobute New Materials Co. Ltd.，Nanjing 211103，China；2.College of Materials Science and Engineering，Southeast University，Nanjing 211189，China）
Abstract：The influence of expansive agent and mineral admixtures on deformation and mechanical properties of concrete at early age were researched in this paper. The results show that，the strength of compressive concrete at early age increases by 6%~17%，and the splitting tensile strength at early age decreases by 27%~42% after adding expansive agent. However，it has little effect on the mechanical properties of concrete at the age of 28 days. The elastic modulus of concrete at early age generally has a decreasing trend after adding expansive agent，and the dynamic elastic modulus of expansive concrete decreases by 1.5~7.3 GPa at the age of 28 days. Due to the effectiveness of expansive agent，expansive concrete can store large expansion deformation at early age，which has compensated the shrinkage of concrete and is conducive to the improvement of crack resistance of structural concrete. The maximum expansion deformation of early age expansive concrete can reach 142 με~315 με. However，when mineral powder is added into expansive concrete，the self-shrinkage of concrete will be significantly increased，and the effect of expansive component of expansive agent will be decreased.
Key words：early age，expansive concrete，deformation，mechanical properties