Laboratory Investigation of Type I and Type II Hardened Cement Emulsified Asphalt Mortar

The research presented in this thesis investigated the mechanical and viscoelastic properties of a relatively new construction building material that has been given a lot of attention in the past decade. Cement emulsified asphalt mortar (CEAM) has unique properties that differ from concrete and asphalt binder alone as this hybrid material combines the high strength of portland cement composites and the flexibility of asphalt materials. Functioning as a damping material for ballastless high-speed rail track bed, CEAM has the potential to be utilized in other areas of construction.

The work presented in this thesis is broken down into two studies, each examining the CEAM over a range of asphalt binder/cement (B/C) ratios. The first study examined the uniaxial compressive strength (UCS), indirect tensile (IDT) strength, tensile strength ratio (TSR), dynamic modulus, phase angle, and shrinkage of type II CEAM at three different B/C ratios. The cement hydration heat of the paste was measured and the microstructures of CEAM were examined to analyze the interaction between cement and asphalt and to explain its effect on the mechanical properties of CEAM. The results from this study showed that CEAM exhibited loading rate- and temperature-dependent properties, indicative of a typical viscoelastic material, and laid the groundwork for the following study.

The second study built upon the results of the first work and examined the mechanical and viscoelastic properties of type I and type II CEAM using cationic and anionic emulsions. Cationic emulsion proved to yield greater strength development at the cost of workability for both type I and type II CEAM. In addition the results showed a sizable difference in measurable properties at the highest and lowest B/C ratios while indicating possibly comparable results mid-range B/C ratios showing the versatility of the material.