Summary The compressive strengths from the concrete cylinders are the main focus of this report although air and proctor tests were also conducted.
The tests conducted in the LAOP conform with the standards approved by the American Society of Testing Materials (ASTM) which are briefly described in Appendix A of the report.
This report will focus on five admixtures tested on four different Lafarge cements. One of the admixtures was targeted for possible future commercial use. A brief profile of all of the admixtures and the cement used is given within the report. It was concluded that the admixture called 325-N would yield the highest strength over a 28 day period. It was only better by less than 4% in comparison to the compressive strengths of the other admixtures. Further details on each of the individual trial mixes can be found in Appendix B.
It is recommended that when conducting a program similar to this one that the initial set times and the 24 hour compressive strengths be eliminated as their result reflect to no certain extent how the concrete will stand up over a 28 day period.
Abstract Although Lafarge uses similar processes to manufacture cements at all of its locations across Ontario, the cements at these different locations may perform differently when they chemically react with an admixture due to the nature of the semetitious material at that plant. When testing an admixture across many different cements it becomes more evident that admixtures do not react the same with cements from different location even if they are of the same type. By this it is meant that some cements may result in higher compressive strengths, while other cements may yield very little change or may turn results with side effects such as entrained air.
The dilemma then lies...