technical report documentation page

Myers and Yang (2004) and the values for bridge deck mix A6671 were obtained bycurve fitting the raw data obtained from experiments conducted in this study. The valueof R 2 for bridge deck mix A6671 is comparable to that of the bridge deck mix A 6130.Table 5.2 Comparison of Shrinkage-Time Regression Curve Parameters (General Form)Bridge mix e f e shu R 2A 6671 1.0 21 410 0.977A 6130 1.0 20.8 454 0.987Figure 5.2 compares the shrinkage results for the HPC deck mix Bridge A6671 tothat of Bridge deck mix A6130. The relationship which is shown for both bridge deckmixes represents a comparison of the curve fit equations obtained based on experimentaldata. It can be observed from Figure 5.2 that the shrinkage strain values for bridge deckmix A6671 was 367.16 and for the bridge deck mix A6130 was 406.97. Shrinkage strainof bridge deck mix A6671 was 9.8% lower than the bridge deck mix A6130. Asdiscussed earlier (see Section 1.1), factors affecting shrinkage include mix composition,curing conditions, member size and shape, water cement ratio etc. As observed from themix constituents and proportions (see Section 3.2), the coarse aggregate content was9.9% higher for deck mix A6671 compared to that of deck mix A6130. The courseaggregate tends to restrain the paste matrix such that a lower shrinkage strain for deckmix A6671 was somewhat expected and consistent with the test results. Moreover, thew/cm ratio was also an influencing factor for shrinkage, with lower ratios resulting inconcrete with lower shrinkage. The w/cm ratio was also lower for deck mix A6671compared to that of deck mix A6130, resulting in a lower value of shrinkage strain.32