소수성 칼슘알루미네이트 시멘트(CAC) 복합체의 초기재령의 역학적 특성 및 미세구조 분석

초록

This study evaluated the early-age mechanical properties and microstructure of hydrophobic Calcium Aluminate Cement (CAC) mortar composites mixed with a hydrophobic polymer (PDMS) and a cross-linking agent (TEOS) to enhance the durability of concrete structures. To address the surface treatment issues of inherently hydrophilic conventional concrete, Ordinary Portland Cement (OPC) was mixed with CAC cement, which possesses excellent chemical and fire resistance. A hydrophobic solution, prepared by mixing PDMS and TEOS at a weight ratio of 4:1, was then incorporated at 1.5% or 2.0% to produce the hydrophobic mortar. The fundamental properties of the composite were analyzed through flow, length change, water absorption, contact angle, flexural strength, and compressive strength tests. All mortar variables incorporating the hydrophobic solution exhibited sufficient hydrophobicity, with the water contact angle exceeding 120°, and showed a lower primary water absorption rate compared to the OPC variable7. Notably, the CAC_10_1:1.5_P1.5 mix simultaneously displayed low water absorption and an excellent contact angle8888. This mix also showed delayed strength development after 7 days, but ultimately secured a strength similar to that of OPC. Microstructural analysis (SEM) confirmed that Ettringite crystals and a C-A-S-H gel network were densely formed in the hydrophobic mortar.

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