With the increasing price and carbon dioxide emission of cement comes the challenge of rigid pavement. One of the solutions to address this issue is minimizing the cementitious paste volume (CPV) of the concrete mix with the blended aggregates (BA) technique. This paper presents the effects of minimizing the CPV in Portland limestone cement (PLC) concrete with CPV reduction and BA application for Florida rigid pavement concrete. The findings indicated that reducing the CPV in the pavement concrete mix to some extent would not adversely affect the properties of the pavement concrete; the minimum CPV of PLC pavement concrete mixes can be reduced to 22.5% with no loss in the properties of fresh and hardened concrete. The other benefits of CPV reduction include low permeability and shrinkage strain. In summary, minimizing the CPV and utilizing the BA technique can be considered to design sustainable pavement concrete mixes with better pavement performance, lower materials costs, and lower global warming potential.

The main objective was to develop mix designs for concrete incorporating minimally processed reclaimed asphalt pavement (RAP) materials to be used in the Florida Concrete Test Road. The laboratory program was conducted in two phases. Phase I involved testing of twelve (12) trial mixes to identify feasible mixes which could meet the Florida Department of Transportation (FDOT) specification requirements for pavement concrete. Based on the preliminary test results from the trial mixes, ten (10) production mixes were identified and evaluated more extensively in Phase II to establish the optimum concrete mixes incorporating RAP to be recommended. Concrete mixtures, with 0% to 40% RAP as aggregate replacement and using 20% fly ash and 50% slag as cement replacement, were designed using the optimized aggregate gradation (OAG) technique instead of the American Concrete Institute (ACI) method. Among the RAP concrete evaluated, the 20% RAP concrete mixes with 0%, 20% fly ash, and 50% slag as cement replacement were able to meet Florida Department of Transportation’s (FDOT) over-design compressive strength of 29 MPa (4200 psi) at 28 days. Using 20% and 40% RAP in concrete could result in saving in the total cost of aggregate by 9% and 17%, respectively. When the RAP is not refined (e.g., no washing of RAP, and no separating of coarse and fine portions), it is recommended that 20% of RAP can be used as aggregate replacement in pavement concrete.

A high cementitious paste volume (CPV) can increase the early cracking tendency of the concrete and reduce the durability of concrete pavement. This study investigated the effects of minimized CPV in slipformed pavement concrete (SPC) with blended aggregates (BA). Based on the laboratory results, the performance of pavement concrete with different CPV was evaluated. The CPV of standard SPC can be reduced to 25.0% without affecting its properties as evaluated by compressive strength, drying shrinkage and surface resistivity tests However, the CPV of SPC with optimized aggregate gradation (OAG) using BA technique can be further reduced to 22.5% with satisfactory properties. The SPC mixes with OAG was noted to have better potential performance as a pavement concrete. SPC concrete using Portland limestone cement can give similar properties as those of the conventional concrete using ordinary Portland cement.

Portland limestone cement (PLC) has been used in all classes of concrete in Florida since 2017. In order to comprehensively use PLC, this study investigates the effects of cementitious paste volume (CPV), water to cementitious materials ($\mathrm{w}/\mathrm{cm}$ ) ratio on PLC concrete mixes with or without incorporation of the blended aggregate optimization (BAO) technique. The prelimary results indicated that CPV and aggregate gradation affected the workability, and $\mathrm{w}/\mathrm{cm}$ ratio mainly influenced strength in PLC concrete. Using a lower CPV can improve the electronic resistance and durability of PLC concrete. The findings of this research can help design the proper PLC concrete mix with low cost and environmental impact.

Friction of pavement is the most popular tropic which is concerned by drivers and engineers, surface texture are also widely regarded as key factor to influence it. The brief object of this study is to establish the relationship between 3 D texture and friction. In the study, the mixtures include Dense Grade Asphalt Concrete (DGAC), Stone Mastic Asphalt (SMA), and Porous Asphalt (PA). High Definition Scan Texture Machine (HDSTM) with 2D Laser CCD was adopted to measure the 2 D texture of Asphalt concrete specimens, and British Portable Tester (BPN) was also used to evaluate friction of various mixture specimen surfaces. The study was attempted to further create initial 3 D model with data of HDSTM and Computer Simulation Program. Correlation coefficients between the ratio of Surface area in unit area (SA/A) and friction was up to 0.8. SA/A could be regards as the best feasible factor to estimate the mixture surface in the ability of skid resistance, and. Based on above results, 3D texture parameter is remarkable for evaluation of friction and is was worthy of further study.

In recent years, laser techniques have replaced the commonly used sand pitch method to measure pavement surface texture. However, the conventional red ray laser charge-coupled devices (CCDs), both the one-dimensional (1D) and two-dimensional (2D) versions, traditionally have been influenced by luminance. The study presented in this paper developed an intelligent texture measurement system (ITMS) with a blue ray 2D laser CCD instead of the red ray CCD used in previous pavement surface texture measurement research, in accordance with ISO 13473-3. In this study’s light tests, a halogen lamp was adopted to simulate the light (Klux). The results indicated that the red ray 2D laser could not read the texture under lighting of more than 5 Klux while the blue ray 2D laser was minimally influenced by the light. In addition, when a 15-cm mask was used, the accuracy of the ITMS improved. Based on the presented results, the blue ray 2D laser CCD was found to be more stable than the red ray 2D laser CCD in texture measurement, and a light-protection mask (more than 15 cm) would further protect the laser from the disturbance of luminance.