Author: haroonkhan
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QUALITIES OF WATER FOR MORTAR
Water is used for construction purposes of Civil Engineering Works such as the construction of earth structures, highway construction, mortar and concrete works, etc. Although water is an important constituent of construction materials, it does not receive the attention due to it particularly in the construction of earth structures and highway construction. However, due importance…
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QUALITIES OF SAND FOR MORTAR
Sand particles are small soil grains of silica. As per the Indian Soil Classification, particles of diameter greater than 0.075 mm and less that 4.75 mm are categorized as sand. Sand is naturally available and may be classified as (i) pit sand, (ii) river sand and (iii) sea sand. Sea sand is not suitable for…
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INTchRODUCTION
The directly as a construction material unless they are combined with some other inert material like aggregates. Thus, a combined material formed by mixing intimately a binding material (cement or lime) with a fine aggregate (sand or surkhi) in a certain proportion and with an adequate quantity of water is called mortar. Here lime or cement…
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COMPARISON BETWEEN CEMENT AND LIME
Although cement and lime are cementing materials, they have different features and properties:
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Heat of Hydration Test
During hydration of cement, heat is produced due to chemical reactions. In a large-scale construction this heat may raise the temperature of concrete to a high degree to as high as 50°C. In such cases low-heat cement has to be used or cooling methods must be employed. The test is conducted using a calorimeter adopting…
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Tensile Strength Test
This test is conducted using a cement-mortar briquette in a tensile testing machine. The dimensions of the briquette are shown in Fig. 6.8. Figure 6.8 Standard cement-mortar briquette A 1:3 cement–sand mortar with water content of 8% is mixed and moulded into a briquette in the mould. It is cured for 24 hours at a temperature…
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Soundness Test
The Soundness Test is performed to detect the presence of uncombined lime and magnesia in cement. This test is conducted in Le Chatelier’s apparatus (Fig. 6.7). It consists of a small brass cylinder of 30 mm diameter, 30 mm height and 0.5 mm thickness, which is split along its generation with the split not exceeding…
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Strength Test
The strength of cement can not be determined directly on cement. Instead the strength of cement is indirectly determined on cement-mortar of 1:3, and the compressive strength of this mortar is the strength of cement at a specific period. For this test, 555 g of standard sand and 185 g of cement is mixed with…
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Setting Time Tests
An arbitrary division has been made for the setting time of cement as the initial setting time and final setting time. Vicat’s apparatus is used for setting times also. 1. Initial Setting Time About 500 g of the cement sample is taken and water content 0.85 P, where P is the percentage of water required as per the…
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Consistency Test
Consistency Test is conducted to find the setting times of cement, viz., initial setting time and final setting time. The test is conducted using a standard consistency test apparatus, viz., Vicat’s apparatus (Fig. 6.6). Figure 6.6 Vicat apparatus with various plungers Standard or normal consistency of cement paste is defined as that water content which will…