Papers by Keyword: Prediction Formula

Abstract: With so many complex influence factors of blasting flyrock, there is no critical formula for prediction the flying distance of blasting flyrock which was adapted by most of the scholars. Widely existing influential prediction formulas are mainly aimed at ordinary blasting technology, using the statistical law or mechanics analysis to get the prediction. The calculated data for flyrock distance are different distinctly. Predictive values are different largely between various formulas. Moreover, when loose blasting, the values predicted by those formulas will be larger than the actual data. This situation wastes lots of human and financial resources for blasting alert. In view of the present situation, the field experiment of loosening blasting was carried and the impacts of blasting parameters to the flyrock distance in loosening blasting were considered respectively. Some blasting parameters were regressed to get a prediction formula. The correlation analysis indicates that the formula for loosening blasting is good for flying distance.

Abstract: To propose a prediction formula of compressive strength of concretes containing fly ash (FA concrete), over 1600 strength data are collected from previous studies and discussed in this study. In particular, the study focuses on developing strengths of FA concrete. The study deals with test data of concrete with wide range of FA replacement, namely 0-50% by mass of cement. Compressive strength at age of 7 days has strongly relation to the cement-water ratio, so the strength can be predicted by using only water and cement contents. In addition, early age strengths within 7 days can be estimated by using the Goral curve based on strength ratio. Strength after the age of 7 days can be predicted by using replacement ratio of fly ash because the strength ratios are proportional to the replacement ratio. Based on the findings, a simplified formula for predicting compressive strength at various ages is proposed in the paper.