Concrete is a construction material that can be highly complex, as it consists of different ingredients with various functions. And the properties of concrete will be contingent on the mixture of its ingredients: cement, lime, water, aggregates, and admixtures.
Your concreting project will succeed if it involves excellent planning, correct practices and the right concreting tools. Meanwhile, most of the repair and maintenance problems in buildings result from malpractices in concrete constructions. As such, this article explores what you should do to make your concreting job unproblematic.
Avoid Cold Weather Pours
During springtime and warm weather, there is a dramatic increase in outdoor construction jobs. In these seasons, concrete work is widespread regardless if the concrete is used as an equipment platform, pedestrian zone, road curbs, or to cover a buried pipe.
This is because warm temperatures are the best for pouring concrete. In contrast, below-freezing temperatures may harm concrete, especially if precautions are not followed. As such, when pouring concrete, good practices such as stopping concrete work on a freezing day to prevent cracking and honeycombing must be followed.
Prepare the Site in Advance
Before the delivery of concrete, you must ensure that you have adequately prepared your site. For example, a poorly compacted sub-base can harm your final concrete base. Moreover, when you do not compact the sub-base sufficiently, you could end up with uneven surfaces resulting in a greater risk of weak points.
Concrete mixtures are formulated to target a specific compression strength upon curing. And contingent on the ratio of the following materials: air, water, cement, admixtures, the strength of a mixture can be altered. So, not only is it crucial to specify the type of mix you want but caution must be taken to ensure that you will ultimately receive the right product. Hence, you must obtain every copy of material and receipts to document your work.
Once the cement is laid, it is crucial to carry out a full concrete finishing; the concrete must be compacted to ensure its durability and strength. And smoothing the surface with concreting tools ensures the finish is even and level.
Selecting and Constructing Appropriate Formwork
Formwork is positioned around the selected area’s perimeter and will dictate the shape and extent of every concrete work. And formworks are usually metal forms for concrete pours and must not have any ridges or defects to ensure the pour will be even and consistent.
They must be removable once the concrete is given adequate time to set. And it is a good practice to cover forms in oil or steep them in cold water prior to use to mitigate adherence.
Finally, it would be best if you considered future work when building formwork. The contractor may have to provide sleeves or other openings to install piping or conduits later on.
Concrete must be appropriately placed, and its workability and consistency must be sufficient to place and consolidate it into a solid mass free of any voids or pockets. Meanwhile, an air pocket commonly appears below or behind reinforcing steel bars, especially in locations where there are many bars together.
So, it is crucial to apply proper vibration in this process. Adequately vibrate every concrete with special attention around jammed reinforcements.
In the meantime, rock pockets are locations where there is insufficient cement paste to close spaces between large aggregates. And ensure there is no standing water before concrete placement and avoid transporting concrete to large distances from where it is initially poured. But in many cases, the use of self-consolidating concrete can lessen many of these concerns.