Planning and Site Preparation
Today we will discuss about the planning and site preparation for concrete. But 1st we have to understand what planning is; and what is the need of planning and site preparation before getting into civil work.
If we elaborate it in a simple way, we can say that planning makes your work simple and straight, doesn’t matter what kind of work we are doing.
Also, planning helps to get our work done before the completion period. This is the main reason why planning is necessary for all kind of works.
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Planning
Planning in Civil Engineering means a pre-production activity which consist of various steps i.e. drawing of construction plans, material preparation, safety of all the people linked with the specific work, staff recruitment, plant and workers.and the most important is getting permission of local authority to construct. In simple way, planning means what to do, when to do, how to do.
It also includes preparing necessary data sheet daily, weekly and monthly, budgeting and many more. Planning engineers decides or develop the fundamental models or methods for the particular project that should be economical as well.
Site Preparation
Site Preparation means demolition or wrecking of building or any other structure, clearing up the sites, barricading the site for safety purpose so that it will not affect the local people, excavation, grading and compaction, soil testing, site marking etc. We will discuss all the factors in detail.
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Steps In Preparing Site for Construction Project
- Technical report related to soil property.
- Site clearing and excavation
- Grading of site
- Site compaction
Technical report related to soil property
Every zone has unique soil property so it is very necessary to know whether the construction on the soil will be suitable or not. For this, there are different types of tests which will give the information about the bearing capacity of soil. Bearing Capacity means the load bearing power i.e. how much load a soil can bear on itself. Field test like Plate Bearing test, Standard Penetration test, California Bearing Ratio test etc are generally used to identify the bearing capacity of soil.
After achieving the test result; the type of foundation, soil strength, soil classification and many other necessary details will be provided in the report. Therefore, to understand the properties and condition of the soil of the site, a geotechnical report of the site is must.
Site Clearing and Excavation
Site clearing and excavation is a major job in site preparation. You have to clear all the unwanted trees and vegetation from the site. After this, marking of the site will be done by the help of an instrument called as Total Station.
After the marking; the excavation work begins and soil is excavated to the required depth in which the foundation work is done. There are various type of machines used for excavation. For eg. power shovel, bulldozer, earth movers etc.
Grading of Site
Grading is the process of adjusting the slope of soil around the building or any structure that will be constructed. The primary concern of Site Grading is to control the flow of storm water.
According to International Building Code, the slope should be 5% at a distance of 3m measured perpendicular from the surface of the wall. Final settlement of soil will be considered after while grading is carried out.
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Site compaction
Compaction of soil layers which support loads is very necessary because it decreases the settlements and prevent undesired incidents. Tamping, Rolling and Vibration are the types of loads used for the compaction of soil. Compaction ultimately improves the strength and decreases the soil permeability. Bad compaction and poor grading led to cracking in the building.
Site Preparation for Concrete
While doing concreting, safety of the workers, supervisor and all the persons indulge in the project is the major concern. Workers at the site should always wear protective clothes, strong boots, helmets and eye protection. Always avoid direct contact with cement and never touch the concrete mix directly. Always use gloves for this.
Always ensure that anyone,if using heavy equipment has been properly trained. Lets discuss thoroughly the various steps while preparing concrete work.
Formwork
Formwork is a term used for the process of creating a temporary mould into which concrete is poured.The material used for making formwork are timber, steel, glass fibre reinforced plastics etc. It is also known as Shuttering. It is then adjusted by the help of scaffoldings.
Services
Plumbing, Heating or electrical services must be in place before the concrete is poured.
Reinforcement Location
As the name suggest, to reinforce means to make it stronger. In civil engineering the term reinforcement is used for the steel bars we put inside the concrete. The reinforcement must be covered by an amount of concrete to prevent the steel bars from rusting, known is cover or cover blocks.
The amount of cover depends on whether it is inside or outside and is measured from the top or bottom of the outer surface.
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Access
Clear access must be provided to transport the concrete easily. In maximum cases, the concrete is to be transported or delivered by trucks so we have to make sure that they have unrestricted access to the site in all weather conditions.
Joints
The position, type and the number of joints should be planned well before the concrete is placed.
De-shuttering
De-shuttering will be done after 1-2 days after the placement of concrete. This time will be increase for slabs and footings upto 4 days depending upon the length of span.
Watering/Curing
Curing will be done immediately after placement and finishing of concrete to achieve maximum strength. Curing can be done by spraying or sprinkling water or any curing agent over the surface of concrete structure. A maximum of 28 days curing will be done to achieve 99% of the strength.
NOTE that no structure will attain 100% strength even after 28 days of curing due to Creep Effect.
