Trials of grade 100 high–strength concrete

This paper describes the site trials for a grade 100 high–strength concrete project conducted in Hong Kong. The data presented include cube strength, core strength, the effect of different methods for core end preparation and in situ temperature monitoring. The results have shown that a concrete having a water–to–binder ratio of 0·22 and a binder content of 700 kg/m3 can achieve an average in situ cube strength of 116 MPa and a core strength of 105 MPa at 28 days. The cube strengths have a standard deviation of 8 MPa, giving a characteristic strength of 102 MPa. The peak in situ temperature can be controlled to below 85°C with appropriate cooling measures. Significantly, this work has confirmed the notion that high–strength concrete is more robust against elevated–temperature curing and found that high–strength concrete may have a higher core/cube ratio than conventional concrete.