Shrinkage and Weight Loss Development for Normal Strength Concrete
Abstract
The paper presents outputs from an investigation carried out to study the relationship between drying shrinkage and weight loss of plain normal strength concrete (NSC). Two crushed limestone aggregate concrete mixes of grade 40 and 60 MPa had a water /cement ratio (W/C) 0.56 and 0.5 respectively were tested. In addition two other identical gravel aggregate concrete mixes also tested (Limestone and Gravel denoted in this paper results by L and G respectively). The maximum aggregate size used in all concrete mixes was 14mm. All specimens were subjected to standard air drying in a temperature and humidity controlled room (RH 65±5%, and temperature of 20±2C0) for 100 days. The test specimens were dried by an oven to 105 ± 5°C, after the 100 days regime terminated and the final values for shrinkage and weight loss reported. It was found that shrinkage and weight loss had an approximately linear relationship in the experimental period considered, and similar behaviour for both gravel and limestone aggregate was observed. It was also noticed that the moisture loss by oven drying had increased with direct relation to specimen size, but the shrinkage results are comparable to that of air drying and slightly affected by the specimen size.
