Series-II: Analysis of Construction Practices
Purpose of the article: Poor construction methods and neglecting basic construction practices - will lead to reduction in strength and life span of a building. The advantage for builders (or) contractors is that - such aspects of building (like strength and lifespan) can not be assessed or noticed immediately. Any such problems will start after 15-20 years. So, it is giving an opportunity to use low-grade materials and neglect basic practices.
Customers are also assessing a building - based on amenities, elevation and paints. They should put extra effort to identify quality of materials used and construction practices followed. Purchasing of house/flat is one-time activity and involves big financial investment. Please note that certain aspects of building can be repaired or remodeled, but not all (like foundation, slab, columns).
Customers are also assessing a building - based on amenities, elevation and paints. They should put extra effort to identify quality of materials used and construction practices followed. Purchasing of house/flat is one-time activity and involves big financial investment. Please note that certain aspects of building can be repaired or remodeled, but not all (like foundation, slab, columns).
II. CONSTRUCTION PRACTICES
Practice | Correct & Standard | Incorrect & Unfair (what is happening on ground nowadays) |
---|---|---|
CURING (WATERING) | - Curing plays an important role on strength development and durability of concrete - Curing should be done at regular intervals - Adequate number of watchmen and monitoring their work | - Most important, yet most ignored and abused construction practice - No record or proper monitoring is done - Inadequte number of watchmen, no monitoring |
- SLAB: Curing should be done for minimum 14-days - No work should be allowed on slab for first 4 days after slab - Store water on slab by creating small ponds using cement mortar bunds(kattalu) - Make sure cement mortar bunds are repaired at the end of work everyday | - SLAB: Curing is stopped and next slab work is started as early as on 11th day - Extension of column rods and column work is done on 3rd day - Cement mortar bunds are not setup, if they are broken during other works. | |
- COLUMNS: Curing should be done for minimum 7 days - Curing should be done regularly(once in 3 hours) during first 3 days - Tying of gunny bags around columns improve moisture around columns | - COLUMNS: Curing is done 3-4 days and then centring work will start - Curing is done 3 times a day (morning-afternoon-evening) - No gunny bags are tied around columns | |
- BRICKWORK and PLASTERING: Curing should be done for 7 days - Curing schedule should be noted, to make sure all walls are cured | - Hardly any watering after first 3 days work - Next step of construction works are started immediately | |
FOUNDATION | - MARKING OF COLUMNS: Proper and technical methodologies should be used at every stage of marking - Only one tape(that too, steel tape) should be used throught out foundation measurement marking - Do the marking of columns at every stage, even though it is cumbersome process. - Make sure that deviation of columns marking should not be more than 1/2-inch. | - MARKING OF COLUMNS: Only initial and final stage markings are done technically. - At other stages, marking of columns are done relative/referencing to adjacent column. - Usage of plastic tapes and different tapes, give deviations in measurements. - Ultimately, column rods are bent 1"-2"inches as per marking and effecting strength of design. |
- PILES/FOOTINGS: Piles/footings should be done as per drawing. - Any earth material should be removed and basement for concrete should be setup as required. - Columns from piles/footings should be 90-degrees vertical to the ground. They should not be inclined. | - PILES/FOOTINGS: Concrete and steel rods are followed as per drawing. - However, any earth material is not removed properly during the stages. | |
BACKFILLING, BASEMENT & COMPACTING | - BACKFILLING: This is mainly applicable in Open Foundation structures. - After backfilling with soil, compacting should be done thoroughly in multiple stages to set the soil. - Only sand/dust/flyash should be used, with proper compacting methods, for raising basement height. - COMPACTING - should be done in iterations for setting of the soil. | - BACKFILLING: Earth soil (or) stone & dust is used for filling as it is cheaper. - A layer of dust/flyash is poured above this and bed concrete will be done. - Compacting techniques doesn't work on these backfilling materials. - This will lead to shrink/basement going down after sometime. |
CONCRETE MIX (for slabs & columns) | - CONCRETE MIX: 3 aspects to be taken care. - Material proportion: If M20, generally 1:5:7 (1 cement bag, 5 sand gamelas, 7 metal gamelas). - Material quality: Refer to other article on materials to be used. - Mix method: Adequate water should be used, final mix should not be juicy/liquid. - For columns, mix is 1:4:6 (1 cement bag, 4 sand gamelas, 6 metal gamelas) - Separate supervisor to exclusively monitor concrete mix quality and proportions. | - CONCRETE MIX: - Material proportion: 1:6:8 (1 cement bag, 6 sand gamelas, 8 metal gamelas). - Material quality: Refer to other article on materials to be used. - Mix method: More water is mixed, so that final output is juicy and work can be completed quickly. - Due to more sand and metal in each load, work will be over in quick time with less number of cement bags. |
BRICKWORK | - Before starting brickwork, surface should be cleaned till slab surface. Any extra cement-mortar portions should be removed. - Before using bricks, make them wet by pouring water. - Apply cement-water mix on columns, so that brickwork attachs to column. - Only 3-feet height of wall should be raised per day. - Steel lintel should be setup after 5-feet in 4-inches wall. - Two walls should be jointed using "stepped expansion". | - Continuous brickwork without any procedures - Gives cracks easily and inferior strength |
SUPERVISION | - SUPERVISORS: Sufficient number of supervisors should be there to monitor work practices. - Civil background experienced supervisors are mandatory during super structure of building. - The fear of supervision itself makes workers to follow proper practices. - SITE ENGINEERS: Site engineer should visit site on regular basis. - His vast experience assists in planning sanitary, water supply & electrical setups. - They suggest solutions to problems, which are already faced in other buildings. | - SUPERVISORS: - Supervision is handled by two people: One Experienced Supervisor and Tapi Mestri. - Entire super structure construction is handled by them, no site engineer visits. |
Afterword: In this world of CONTRACT basis work, basic construction practices are being ignored to reduce the cost and speed up work. It is effecting strength and lifespan of a construction, which can not be realized immediately. Customers should be extra cautious before taking a decision.