Flexural Strength Flexural strength is an indirect measure of the tensile strength of concrete. It is a measure of the maximum stress on the tension face of an unreinforced concrete beam or slab at the point of failure in bending. It is measured by loading 150 x 150-mm (or (100 x 100-mm) concrete beams with a span length …
Purpose of test To determine the specific gravity of soil fraction passing 4.75 mm sieve by pycnometer. Use of specific gravity value The knowledge of specific gravity is needed in calculation of soil properties like void ratio, degree of saturation etc. Definition Specific gravity G is defined as the ratio of the weight of an …
Effect of SCMs on Alkali-Silica-Reaction Mitigation 1- Fly Ash the three characteristics of fly ash that determine its efficiency in preventing ASR are fineness, mineralogy, and chemistry. In general, the finer the fly ash, the more efficient it is in reducing ASR expansion. An ultra fine fly ash, with particle size around 3 μm, can …
Concrete Spalling Currently, there are two mechanisms concerning the occurrence of spalling: 1- the pore pressure build up causes spalling in the cement matrix and 2- thermal and mechanical stresses. In 1997, Anderberg gave an account on spalling caused by vapour pressure. The mechanism is believed to be the same for both High Performance Concrete (HPC) …
Soil Testing Required for Road Construction Generally, when it come to construction on soils, tests should be performed to understand the nature of soil that the building is going to be constructed on. In this article, the basic tests required for the construction of roads and highways are briefly mentioned. Common test are: Soil classification, particle …
Corrosion of Embedded Metals in Concrete Corrosion of reinforcing steel and other embedded metals is the leading cause of deterioration in concrete. When steel corrodes, the resulting rust occupies a greater volume than the steel. This expansion creates tensile stresses in the concrete, which can eventually cause cracking, delamination, and spalling (Figs. 1 and 2). …
Causes of Formwork Failures Failure of formwork in general results from various causes: excessive loads, premature removal of forms or shores, inadequacies related to formwork, and human error on the job, whether due to indifference, haste, or lack of knowledge. Hadipnono and Wang (1986) studied the causes of 85 major falsework failures that have been documented …
Concrete repairs have occurred on Reclamation projects since the first concrete was placed in 1903. Unfortunately, even though the best available knowledge and materials were used, many repair failures have occurred during the 112 years since that first concrete was placed. As a first step to increase the likelihood of a successful repair, it is …