| Abstrakt: |
Summary The assumption that a change of consistence in a concrete mix that is due solely to a change of water content is independent of the composition of the mix (type of cement, cement content, original water content, original water/cement ratio, air content, grading and maximum size of aggregate) is tested and shown to be valid within wide limits. This assumption is called “assumption of independence” and its use in the prediction of consistence is called “k procedure”.In the appraisal of this assumption, it is first proven mathematically that the assumption of independence is identical with the assumption that the consistence of concrete is a parabolic function of the water content, and the degree of the parabola is independent of the composition. Then it is shown that for six methods of measuring consistence the experimental results substantiate the existence of such a parabolic relation within wide limits.A parabolic formula for the k thinning factor is derived, and its numerical forms for six methods of measuring consistence are presented. It is shown for various cases that the use of the k factor in the prediction of consistence is simple and the calculated results are in accordance with experimental data.Summary The assumption that a change of consistence in a concrete mix that is due solely to a change of water content is independent of the composition of the mix (type of cement, cement content, original water content, original water/cement ratio, air content, grading and maximum size of aggregate) is tested and shown to be valid within wide limits. This assumption is called “assumption of independence” and its use in the prediction of consistence is called “k procedure”. In the appraisal of this assumption, it is first proven mathematically that the assumption of independence is identical with the assumption that the consistence of concrete is a parabolic function of the water content, and the degree of the parabola is independent of the composition. Then it is shown that for six methods of measuring consistence the experimental results substantiate the existence of such a parabolic relation within wide limits. A parabolic formula for the k thinning factor is derived, and its numerical forms for six methods of measuring consistence are presented. It is shown for various cases that the use of the k factor in the prediction of consistence is simple and the calculated results are in accordance with experimental data. |
