General requirement and limiting values of impurities of water
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This document discusses the requirements and limiting values of impurities in water used for concrete. It outlines three purposes that water serves in concrete: 1) wetting aggregate surfaces to improve adhesion, 2) imparting workability to the mixture, and 3) enabling hydration and curing of cement. Water quality can impact the strength of hardened concrete. The document recommends comparing setting time and mortar cube strength when using new water sources to establish suitability. It lists maximum limits of 500 ppm for chlorides, 1000 ppm for SO3 and alkali carbonates/bicarbonates, and 2000 ppm for turbidity in mixing water.
General requirement and limiting values of impurities of water
- 1. S.N. PATEL INSTITUTE OF TECHNOLOGY AND RESEARCH CENTRE TOPIC:- General requirement and limiting values of impurities of water
- 3. Concrete:- • Concrete is a chemically combined mass which is manufactured from binding materials and inert materials with water.
- 4. Function of Water in Concrete:- Three water serves the following purpose:- 1. To wet the surface of aggregates to develop adhesion because the cement pastes adheres quickly and satisfactory to the wet surface of the aggregates than to a dry surface.
- 5. 2. To prepare a plastic mixture of the various ingredients and to impart workability to concrete to facilitate placing in the desired position. 3. Water is also needed for the hydration of the cementing materials to set and harden during the period of curing.
- 6. • The quantity of water in the mix plays a vital role on the strength of the concrete. Some water which have adverse effect on hardened concrete. Sometimes may not be harmless or even beneficial during mixing. So clear distinction should be made between the effect on hardened concrete and the quality of mixing water.
- 7. • Determination of Suitability of Mixing Water:- • A simple way of determining the suitability of such water is to compare the setting time of cement and the strength of mortar cubes using the water in question with the corresponding results obtained using known suitable or distilled water. About 10% tolerance is generally allowed. Such tests are recommended when water for which no service record is available containing dissolved solids in excess of 2000 ppm or, in excess of 1000 ppm. When unusual solids are present a test is also advisable.
- 8. Quality Parameters Maimum Limit (ppm) • Chlorides 500 • SO3 1000 • Alkali Carbonates and Bicarbonates 1000 • Turbidity 2000
- 9. Thank you