Needle Penetration Test Essay

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3. LABORATORY TESTS USED TO STUDY THE STRENGTH OF CALCARENITES There are 3 distinct methods or tests used to determine the strength of calcarenite which are needle penetration test, unconfined compression test, and direct shear box test. 3.1. Needle penetration test This form of test is done on site on an outcrop rock that is not disturbed; this is usually done by extracting a sample material for oncoming laboratory work. The penetration tests are done on two different sections of outcrop with an in-between distance of about 15 metres. A frequently used apparatus is a spring-loaded pocket penetrometer made by Eijelkamp, the Netherlands. What makes it special is that it does not have a cone like most penetration instruments but has a needle of hardened steel to make it…show more content…
PROBLEMS ASSOCIATED WITH BUILDING ON LANDS WITH CALCARENITE. When it comes to problems that are associated with building on grounds with calcarenite, some are natural and some are inherent and they are as follows. 4.1. Weathering When the calcarenite is subjected to exposure to different atmospheric conditions it deteriorates due to natural effect of rain, wind and thermal change. The rock is durable as water infiltrates it becomes extremely reactive when exposed to acids and then suffer deterioration. After it has deteriorated it can no longer withstand the pressure of the building on top of it and as a result, it sinks to the ground. Since it is a natural factor very little can be done to counteract this or to solve the problem caused by weathering. 4.2. Erosion Erosion is a result of general weathering and air caused abrasives may selectively wear away detailing on certain elevations based on the direction of occurring winds. It does not really affect the building precisely but the water the inhabitants of the building depend on. Sediments get deposited into water bodies and therefore dirty and pollute the water such that the dependents may fall sick of the water and also it reduces

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