Optimization Design of the Mix Ratio of a Nano-TiO2/CaCO3-Basalt Fiber Composite Modified Asphalt Mixture Based on Response Surface Methodology

Yafeng Gong,Jiaxiang Song,Haipeng Bi,Zhenhong Tian

doi:10.3390/app10134596

Abstract

This research optimizes the mix ratio of nano-TiO2/CaCO3 (NTC)-basalt fiber (BF) composite modified asphalt mixture. Based on the Box–Behnken method and the response surface method, a three-factor and three-level test was designed. The input indicators were the asphalt–aggregate ratio, NTC content, and BF content. The output indicators were the density, air voids, Marshall stability, flow value, voids in mineral aggregate (VMA), and voids filled with asphalt (VFA) values of the asphalt mixture. The response surface model was established according to the test response index value. Then, the function was fitted through multiple regression equations and multivariate analysis of variance was performed. Finally, according to the specification requirements and engineering needs, the selected conditions of each response value were determined to optimize the asphalt–aggregate ratio and the contents of NTC and BF, and the predicted values were verified through the measured data. The test results show that the optimal contents of NTC and BF and the optimal asphalt–aggregate ratio were 5.1%, 3.9%, and 5.67%, respectively. By comparing the measured Marshall test index value with the predicted value, the minimum relative error was 0.096% and the maximum error was 6.960%. The results show that response surface methodology can be used to optimize the mix ratio of composite modified asphalt mixtures.

Highlights

In recent years, with the increase of traffic flow and the deterioration of the environment, it is becoming increasingly difficult for existing asphalt pavement to meet requirements, meaning modified asphalt technology is very important
The NTC content, basalt fiber (BF) content, and asphalt–aggregate ratio were independent variables, while the density, Marshall stability, flow value, air voids, voids filled with asphalt (VFA), and voids in mineral aggregate (VMA) were responses or dependent variables
Based on the response surface method, this research adopted the Box–Behnken design method to carry out a three−factor, three−level design

Summary

Introduction

With the increase of traffic flow and the deterioration of the environment, it is becoming increasingly difficult for existing asphalt pavement to meet requirements, meaning modified asphalt technology is very important. With the emergence of nano-modified and fiber-modified asphalts, the performance of asphalt pavement has been effectively improved, and the service life of asphalt pavement has been improved. Due to the large specific surface area of the nanomaterials, after being added to the asphalt, the nanomaterials can improve the cohesion and increase the viscosity and high temperature stability of the asphalt, thereby improving the high temperature performance and water stability of the asphalt mixture. Chang et al [2] added different proportions of nanometer calcium carbonate to SBS (styrene–butatriene–styrene) modified asphalt and analyzed the high- and low-temperature stability of the composite modified asphalt via changes of the nanometer calcium carbonate content.

Methods

Results

Conclusion