Bond Performance of Thermally Shocked Foam, Normal Concrete, and Carbon Fiber–Reinforced Polymer Sheets in Anchorage Systems

Abstract

Using foam concrete (FC) as a building material is a new way in the construction world to gain many advantages that are not available in normal concrete. Therefore, this research investigates the potential for anchoring carbon fiber reinforced polymer (CFRP) sheets attached to thermally shocked normal-weight aggregate concrete (NWAC) and FC by employing CFRP ropes and U-wrapping CFRP sheets. A total of 64 concrete prisms with dimensions of (150×150×200 mm) was prepared using two concrete mixtures. The specimens were damaged by thermal shock and tested given a pull-out force. The thermal shock regime involved heating to 500°C for 3 h and then rapidly cooling for 15 min in water. Six types of anchorage systems were used that were divided into two main groups: fan and U-wrapping anchorage systems. The experimental results showed that using CFRP anchorage techniques significantly enhanced the mechanical performance of undamaged and damaged specimens. In contrast, the most effective anchorage technique was to use two fans, which increased the ultimate bond load, slippage, stiffness, and toughness by average percentages of 92.82%, 84.24%, 159.57%, and 259.62%, respectively. The effectiveness of the fan anchorage systems was influenced by the number and distribution of the legs. Similarly, the U-wrapping anchorage systems’ efficiency in undamaged specimens was only influenced by the width of the U-wrapping sheet. The mechanical properties and performance of the FC and NWAC prisms were considerably impacted by thermal shock. This effect can be described as a decrease in the ultimate bond load and stiffness and an increase in slippage and toughness.