Cationic asphalt emulsion as an additive of RCC Pavement: Exploring for Mode-I fracture behavior and dynamic modulus properties

So far, several studies with the aim of investigating the feasibility of applying emulsified asphalt as an additive in the different types of cement concrete have been conducted, of which the results show a promising performance. Nonetheless, a relevant study on the dynamic and cracking behavior of Roller Compacted Concrete (RCC) containing Cationic Emulsified Asphalt (CEA) have been seldom accomplished. Therefore, it paved a way for studying this issue by conducting ex-periments on cylindrical and semi-circular bending (SCB) specimens made with CEA contents of 0, 2, 4, 6, 8 and 10% by weight of cement. The SCB specimens were subjected to three-point bending test (mode-I fracture) to evaluate the effect of CEA on the fracture properties. The cy-lindrical specimens were subjected to dynamic modulus testing with sinusoidal loading/ unloading with different frequencies (5, 2, 1, and 0.5 Hz) as per AASHTO T342 to assess the effect of CEA on the dynamic modulus. Non-destructive ultrasonic pulse velocity (UPV) test was also performed on the cylindrical specimens 200 x 100 mm, which were prepared by cutting 50 mm disc from two ends of the specimens. Applying multiple linear regression on experimental results, a set of models were thus developed for estimating mechanical properties based on UPV mea-surements at a 95% confidence level. Using ANOVA at a 5% significance level, the results revealed a significant decline in stress intensity factor and thereby cracking resistance following the addition of 4% or more CEA to the mixture. Adding 6% or more CEA significantly reduced the mixtures' dynamic modulus but also significantly increased their fracture energy. Given that adding CEA and changing the loading frequency, respectively, had no significant impact on the mixtures' phase angle and mechanical properties, it was concluded that the behavior of the RCC made with CEA additive remained within the linear elastic range.

Automated summary

So far, studies on the feasibility of using emulsified asphalt as an additive in different types of cement concrete have shown promising results. However, there is limited research on the dynamic and cracking behavior of Roller Compacted Concrete (RCC) containing Cationic Emulsified Asphalt (CEA). This study conducted experiments on different specimens to assess the effect of CEA on fracture properties, dynamic modulus, and mechanical properties of RCC. The results showed a decrease in cracking resistance with the addition of 4% or more CEA, while an increase in fracture energy was observed with 6% or more CEA. The behavior of RCC with CEA additive remained within the linear elastic range.