TRAFFIC DETECTOR HANDBOOK TECHNICAL APPENDIX: SUMMARY OF REFERENCES

The rapid rate of construction has created a need to have information on the strength of concrete at the earliest possible time. Having to wait 28 days before the strength can be determined can cause serious problems if inferior concrete had been used in a member or a section which is already in place. In this study the ASTM C-684, making, accelerated curing, and testing of concrete compression test and specimens, was examined. Procedure A, the warm water method, and procedure B, the boiling water method, were evaluated using two types of coarse aggregate, locally available chert gravel and Kentucky limestone. Concrete cylinders were tested after being cured by each accelerated curing method and normal moist curing. The data from each accelerated method was plotted against the normally cured 28-day strength and the best fit curve was determined. Also, an equation was established for each procedure and each curve. From the data indicated in this report and literature searched, it seems that accelerated curing methods can be used reliably to estimate the actual 28-day strength. (Author)