| 摘要: |
| 为解决湿热地区混凝土碳化破坏严重的问题，在室内模拟湿热环境，通过碳化试验研究了超吸水性树脂（SAP）粒径和掺量对混凝土抗碳化性能的影响；采用扫描电子显微镜（SEM）对碳化前后混凝土的微观形貌进行分析；采用压汞仪（MIP）对混凝土不同层位的孔结构进行剖析.结果表明：SAP材料可有效提高混凝土的抗碳化性能，且随着碳化龄期的增长，混凝土的抗碳化性能显著提升；虽然SAP的掺入增大了混凝土的孔隙率，但可以细化各层位之间的孔结构，降低孔隙间的连通性；SAP释水后在孔隙外部形成较为致密的环形层，且SAP促进水化可以较好地填充孔隙，减少裂缝数量和尺寸，从而抑制CO2的扩散，改善了混凝土的抗碳化性能. |
| 关键词: 道路工程 SAP内养生混凝土 抗碳化性能 微观形貌 孔结构分布 |
| DOI：10.3969/j.issn.1007-9629.2022.01.003 |
| 分类号:U414.1 |
| 基金项目:国家自然科学基金资助项目（51778061） |
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| Investigation of Carbonation Resistance and Mechanism of SAP Internal Curing Concrete in Humid and Hot Environment |
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GUO Yinchuan1, HUANG Zhongcai2, WANG Wenzhen1, SHEN Aiqin1, LI Desheng3
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1.Key Laboratory of Highway Engineering in Special Region of Ministry of Education， Chang'an University， Xi'an 710064， China;2.Guangxi Chongrui Expressway Co.， Ltd.， Nanning 530028， China;3.China Highway Engineering Consultants Group Co.， Ltd.， Beijing 100089， China
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| Abstract: |
| In order to solve the severe carbonization problem in hot and humid regions， the hot and humid environment were simulated in laboratory， the carbonization test was conducted and the effects of particle size and use level of super absorbent polymer（SAP） on the carbonation resistance of concrete were investigated. By using scanning electron microscope（SEM）， concrete microscopic morphology before and after carbonation test were identified， and based on mercury intrusion meter（MIP）， the pore structures of the concrete at different layers were determined. The results show that the incorporation of SAP can effectively improve the concrete carbonation resistance， and the carbonation resistance improved significantly with the increase of carbonization age. Although the incorporation of SAP increases the porosity of concrete， it refines the pore structure between each layer and reduces pore connectivity. Furthermore， after SAP releases water， a higher density region is formed outside the pores， and SAP promotes hydration to fill these pores， it also reduces the amount and size of crack， thereby SAP internal curing concrete can inhibit the diffusion of CO2 and promote the carbonization resistance of concrete. |
| Key words: road engineering SAP internal curing concrete carbonation resistance micromorphology pore size distribution |
