New Alternative Method for Bonding RCC Layers
Because at weather conditions, work schedules, required RCC volume, or periods of equipment maintenance, the interval between placements of two successive lifts may exceed one day, the cold joint begins to develop, resulting in loss of bond strength and potential increase in permeability. Once me cold joint develop, a bedding layer treatment may be required to achieve the required bond strength, mortar and concrete bedding treatment were most commonly used, both systems have disadvantage where the bedding mortar more expensive, dry out faster, and have higher shrinkage potential, while the bedding concrete is prone to segregation. This paper discusses an alternative method aimed to over come the disadvantage of the above mentioned procedures which is based on the concept of using two stage concrete (TSC) as bedding with modification. This process is thought to have many advantages such as lower cost, low heat generation and shrinkage, no segregation, improve mechanical bond and correspondingly the internal friction angle through the aggregate penetration of the layers. Cylindrical specimens were casted and compacted using vibrating hammer following the soil approach method, which were prepared in two layers or lifts, where the treatment to the first layer was carried out and compacted, then a gap graded coarse aggregate was spread on the smooth layer and injecting the grout to fill the voids between the aggregate particles, the second upper layer of RCC is placed and compacted after 12, 24, 36, 48, 64, and 72 hours. The specimens were kept in water for 90 days of curing, to be subjected for different testing procedures. Also traditional bedding mortar and concrete were used to compare there results with the new alternative method for bonding RCC layers under different strength tests. The obtained results were tabulated and discussed as a relationship between direct tensile, indirect tensile and shear strength versus exposure time showing that, the tensile and shear strength of bond treatment was about 80-100％ of parent RCC strength. Two alternative procedures give higher strength than the traditional procedure which may be considered as a successful step towards improving bonding strength of RCC layers.
Bonding Layer new method TSC
S. Y. Barony M. J. Rouis A. M. Mansor
University of Alfateh, Faculty of Engineering, Tripoli-Libya University De Sfax, Ecole Nationale DInginieurs, De Sfax, Tunis
国际会议
第五届碾压混凝土坝国际研讨会(The Fifth International Symposium on Roller Compacted Concrete(RCC))
贵阳
英文
163-168
2007-11-02（万方平台首次上网日期，不代表论文的发表时间）