A Compressive Peak Strength Model for CFRP-Confined Thermal Insulation Materials under Elevated Temperature

Abstract

In this paper, a compressive peak strength model for CFRP-confined thermal insulation materials under elevated temperature was proposed. The thermal insulation material was made by Portland cement with different portions of perlite. The compressive strengths of four different perlite ratios in weight, such as 0%, 10%, 20%, and 30% of thermal insulation materials, confined by one-layer, two-layer, and three-layer carbon fiber-reinforced polymer (CFRP) composite materials, were obtained. The test results indicated that the specimen’s compressive strength decreased with an increase in the amount of perlite replacement and increased with an increase in the number of CFRP wrapping layers. Based on the test results, a theoretical compressive peak strength model with some parameters was proposed. In the meantime, the compressive strengths of the above four different perlite ratios of thermal insulation materials under elevated temperature, such as ambient temperature, 100 °C, 150 °C, 200 °C, 250 °C, and 300 °C, were obtained. For compression tests of specimens with a fixed amount of perlite, the test results indicated that the specimen’s compressive strength decreased with an increase in temperature, highlighting a thermal softening phenomenon. Based on the test results, a compressive peak strength model with a thermal softening parameter was proposed to predict the peak strength under elevated temperature. Finally, a compressive peak strength model for thermal insulation material with CFRP confinement under different elevated temperature was derived, and it achieved acceptable results in comparison to the experimental results.

A Constitutive Model of High-Early-Strength Cement with Perlite Powder as a Thermal-Insulating Material Confined by Caron Fiber Reinforced Plastics at Elevated Temperatures

“…For the maximum compressive strength of the thermal-insulating material at elevated temperatures, an exponential thermal softening model was proposed as follows [ 38 , 39 ]: where f’ T and f’ c are the maximum compressive strengths of the thermal-insulating material under an elevated temperature ( T ) and the reference temperature ( T ref ), respectively. In Equation (9), λ is the thermal softening parameter of the thermal-insulating materials with various perlite ratios added.…”

A Constitutive Model for Circular and Square Cross-Section Concrete Confined with Aramid FRP Laminates

“…Razvi and Saatcioglu (1998) proposed a constraint equation for high-strength concrete [29]. Li's research proposed the constitutive models for normal-strength and low-strength cylindrical concrete confined with CFRP, which was adopted from the Mohr-Coulomb failure theory to predict the compressive strength of CFRP-confined concrete [30][31][32][33][34]. Wang et al (2012) found that the CFRP-confined-squarecross-section column failed suddenly via CFRP rupture at the corner of the column, and a modified confinement pressure model was proposed which considered the influence of cross-section size, effective rupture strain of CFRP, as well as hoop reinforcement [35].…”