Akademik Veri Yönetim Sistemi
Construction and Building Materials, cilt.418, 2024 (SCI-Expanded)
Roller Compacted Concrete (RCC) pavements, especially in industrial areas, harbors, warehouses, or heavily trafficked roads, often require a two-layer construction due to their greater thickness requirements. Adequate bond strength is typically achieved within one hour of casting the second layer, but after a period of time, interlayer treatments are often required to achieve acceptable bond strength between the two consecutive layers. Traditional cement mortar is the standard interlayer treatment, but alternatives such as latex, bitumen emulsions, epoxy resin, and adhesive mortars are gaining popularity. This study evaluates the bond performance of RCC layers with different treatment methods. Six groups of two-layer RCC slant shear test specimens were prepared and tested under compressive loading. The groups included an untreated group, another group roughened between layers with a metal rake, and those treated with latex emulsion, cationic bituminous emulsion, epoxy resin, and polymer-modified cement-based adhesive mortar enhanced with silica fume. Some of the laboratory test results were later implemented in a two-layer RCC paving project and were verified using cored samples from that project. The results indicate that in laboratory and field test results, two-layer RCC specimens with the adhesive mortar exhibit strength values of 94% and 98% when compared to monolithic/single-layer RCC specimens, respectively. Although the epoxy-treated two-layer RCC specimens experienced separation between layers in the laboratory, they achieved around 85% of the strength observed in the monolithic RCC specimens, ranking second in performance based on the slant shear tests. Cationic bituminous emulsion, common in flexible pavements, acts as a bond breaker and is unsuitable for bonding the two layers of an RCC pavement. In the field, the two-layer RCC pavement without interfacial treatment showed significant performance degradation, achieving only about 50% of the flexural strength of the monolithic RCC road section. This implies that in the presence of cold joints, pavement flexural strength is limited to 50% of the ultimate strength without any treatment. Field testing is essential for accurate interpretations, emphasizing the importance beyond laboratory assessments.