How to avoid Honeycombing in RCC Structures

Definition of a honeycombing: Honeycombing refers to a structural fault in a RCC Structure. Honeycombed surface is the areas of the concrete surface where the coarse aggregate are eminently observable.

If precaution is not taken for honeycombed surface, the RCC structure fails to achieve optimal performance according to its design (structurally weak). Besides, it also lets damaging agents like contaminated water and air entering through the produced voids which can impact the strength of structure considerably.

Causes for Honeycombing: Honeycombing in RCC Structure is happened because of the following reasons -

1. Concrete mix is not homogenous.
2. The applicability of concrete is inadequate and not matched with its placement need.
3. Inadequate compaction to concrete.
4. Concrete flow is not dispersed to all corner due to steel congestion.

5. Concrete is set afore time prior to placing.
6. High free fall of concrete, at the time of pouring
7. Form work is not waterproof or inflexible.
8. Incorrect detailing and/or fixing of steel

How Honeycombing in Concrete can be avoided?

Check concrete production/cohesiveness from time to time to organize all concrete batches.

Tip: If it is possible to create ?ball? from the fresh concrete, a cohesive concrete mix is produced.

Concrete workability should tally with the placement need. As for example, a lightly reinforced column should contain 75mm slump, a heavily reinforced column may require 150mm slump.

Make sure that the compaction of placed concrete is perfect, vibrators should have been detached as big air bubbles stops to come out (over vibration can lead to bleeding). Various sizes (25mm, 40mm, and 60mm) of vibrator needle should have been utilized according to RCC sections.

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Published By
Rajib Dey
www.constructioncost.co
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How to estimate the amount of concrete for pouring a L shaped concrete slab

This construction video briefly explains how to estimate the concrete quantity essential for pouring a L shaped concrete slab in the ground having splayed edge beam and a rebated edge.

Concrete slabs refer to floor systems of concrete and steel reinforcing. These are built on the ground. There are different types of concrete slabs which range from slab on ground, stiffened raft slab, footing slab, waffle raft slab, infill slab.

Edge rebates should be placed in the edge-stiffening beam when exterior walls belong to masonry veneer or complete masonry. A check out from the edge beam will produce a flange for the brick to hinge on under the top of the slab. This extra protection is taken to stop surface run-off water from inflowing the building.

The rebate must be flashed and weep holes are arranged in the masonry. The weep holes should be placed at a least distance of 1.2 metres so that the water can be blown out and left from the wall and the slab.

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Published By

Arka Roy

www.constructioncost.co

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