Construction errors during site concreting can occur due to non-compliance with defined procedures and good practice or sheer carelessness. Some of such failures may not result in concrete collapse or degradation but can have detrimental consequences overtime on the construction.
Table of Contents
Errors During Concrete Construction at Site
The building defects which are likely to arise on site are addressed in depth below with mitigation steps of these. Not only can such failures arise during new development but they may also arise during reconstruction or restoration projects.
Improper consolidation or compaction of concrete
Improper concrete compaction can create a number of defects, the most popular being bugholes, honeycombing, and cold joints. Bugholes are created where the structures become caught in tiny pocks of air or water. To further remove bugholes, a modification in the formula to make it less “sticky” or the use of tiny vibrators in the shape effective.
Honeycombing may be minimized by placing the vibrator more often, by placing the vibrator as close to the face of the form as necessary without hitting the object, and by pushing the vibrator out. Clearly all of more of these flaws make it far simpler for any process that causes harm to start concrete degradation.
Overconsolidation is sometimes used to explain a lack of action in consolidating concrete. Typically, over consolidation is characterized as a condition in which the consolidation attempt allows all the coarse aggregate to settle down whilst the paste rises to the surface.
Adding water to concrete
In either or more of the following cases, water is normally applied to concrete: First, in a shipping vehicle, water is added to concrete to raise the slump and decrease the dumping or positioning attempt. It would result in the concrete of poorer strength and less longevity. If the concrete’s water/cement ratio decreases, strength, and longevity decline.
In the second example, water is usually applied during structural component finishing. This makes the concrete to scale, mad, and crumble.
Improper alignment of formwork: Improper formwork alignment can result in discontinuities at the concrete surface. Although under all instances such discontinuities are unsightly, their presence can be more important under environments that are prone to high-velocity water movement, where cavitation-erosion can be caused, or in lock chambers where the “rubbing” surfaces must be smooth.
Improper curing
Perhaps Curing is the most neglected component of concrete buildings. Unless concrete is allowed enough time to cure at sufficient humidity and temperature, the required and essential characteristics would not be produced to ensure longevity. Symptoms of poorly treated concrete may involve specific forms of cracking and disintegration of the surfaces.
Structural cracking can occur in severe cases where inadequate curing contributes to the failure to attain expected concrete strengths.
Improper location of reinforcing steel:
This segment applies to reinforced steel that is placed improperly or that is not properly installed in the appropriate location. Every such defect can contribute to two kinds of general issues. First, the steel could not work as expected, contributing to structural weakening or failure.
The positioning of welded wire mesh in floor slabs is one especially prevalent example. For certain instances, the mesh stops at the bottom of the slab and would then break as the steel is not in the correct position.
Premature removal of shores or reshores:
Should shores or reshores be extracted so early, the damaged concrete can become overpressed and broken. In severe situations, significant failures may occur.
Settling of the concrete:
The heavier constituents of the concrete may settle under the impact of gravity throughout the time of installation and initial settling of the concrete. This can be compounded by the usage of extremely elastic concretes.
When any restriction attempts to avoid settling, it can result in splitting or separating. Such fractures or separations, once contaminated, may even cause problems of cracking or freezing.
Settling of the subgrade:
Whether during the time after the concrete continues to become solid there is some sinking of the subgrade just until it achieves sufficiently strong to withstand its own weight, cracking may also occur.
The vibration of freshly placed concrete:
Many building sites are vibrated by multiple causes, such as drilling, pile pushing, and heavy machinery operations. Freshly installed concrete is susceptible to degradation of its property if it is exposed to forces during the setting that disturbs the concrete matrix.
Improper finishing of the flat concrete surface:
- Adding water to the surface: proof that water is applied to the surface along with other finishing materials is the appearance of a broad paintbrush. The brush is immersed in wax, and the finished surface is “slung” in wax.
- Finishing timing: Full finishing operations have to be done after the concrete has received its initial collection and leakage has ceased. The waiting time relies on the proportions of water, mortar, and admixtures in the combination but mostly on the concrete surface temperature. The section in the heat should typically be able to end on a partly shaded slate before the portion in shadow.
- Adding cement to the surface: This procedure is sometimes done to dry bleed water to allow finishing to proceed which can result in a thin cement-rich coating that can quickly break or flake off.
- Tamper use: On certain occupations, a tamper or “jitterbug” is used inappropriately. This tool pushes the coarse aggregate away from the surface and can facilitate finishing. However, this activity produces a surface layer of cement-rich mortar that may scale or craze. A jitterbug with a well-made mixture should not be permitted.
