Pouring of concrete for horizontal elements such as beams and slabs is an integral part of building construction. It is advisable to consider specific procedures for concrete placement in order to create a safe work environment and produce sound concrete.
Suitable concreting process prevents adverse effects like segregation and formation of honeycomb, which reduce the durability and strength of the concrete.
How to Pour Concrete in Horizontal Elements?
- Choose suitable concreting equipment like buckets, trucks, and pumps.
- Concrete should have high segregation resistance and low initial bleeding; otherwise, disregard the pumping technique.
- Achieve good segregation resistance and low initial bleeding concrete by using the appropriate quantity of fine aggregate that has fine modulus ranging from 2.2-2.5. Additionally, ensure a low ratio of coarse to fine aggregate, and the introduction of suitable admixtures is helpful.
- Before beginning concreting, get rid of snow, detritus, ice, and water from formworks.
- Check the concrete cover and reinforcement position.
- Damp the surfaces that are going to be concreted.
- Improper concrete placement technique in slabs leads to the occurrence of segregation. As a result, the slab would have high shrinkage and low resistance against weathering influences and abrasive forces.
- Pour concrete continuously close to its final position to keep the concrete quality intact.
- Avoid alteration of concrete composition, for instance, prevent the excess addition of water, keep water to cement ratio as per the design mix, and ensure homogeneity.
- Refrain from dumping a single pile of concrete and then leveling it.
- Avoid pouring a large pile of concrete and then moving it horizontally to its final position.
- Prevent excessive horizontal movement of concrete.
- Keep workability or casting ability of concrete to avoid large plastic settlement and layer lines.
- Begin concreting from one corner of horizontal elements such as slabs.
- Pour each batch against the previous one to avoid excessive horizontal movement of concrete; otherwise, concrete segregation would occur.
- Compact concrete properly.
- If a beam is monolithic with slabs, place the concrete of the beams, and then pour the slab, as shown in Fig. 1.
- For monolithic beams with slabs, extend vibration equipment through the slab into the beam to compact concrete beam adequately.
FAQs on concrete pouring for horizontal elements
Suitable concreting equipment for horizontal elements are buckets, trucks, and pumping equipment.
Achieve good segregation resistance and low initial bleeding concrete by using the appropriate quantity of fine aggregate that has fine modulus ranging from 2.2-2.5. Additionally, ensure a low ratio of coarse to fine aggregate, and the introduction of suitable admixtures is helpful.
Check the concrete cover and reinforcement position, water tightness of formworks, dimension of the concrete element, formwork rigidity etc.
Begin concreting from one corner of horizontal elements such as slabs.
Pour each batch against the previous one to avoid excessive horizontal movement of concrete; otherwise, concrete segregation can occur.
Improper concrete placement technique in slabs leads to the occurrence of segregation. As a result, the slab would suffer high shrinkage and would have low resistance against weathering influences and abrasive forces.
Read more:
How to Pour Concrete in Columns and Walls? [PDF]
How to Pour Concrete on a Sloped Surface? [PDF]