Kenya hasn’t quite yet seen the adoption of pre-cast structural concrete solutions despite the many benefits that they have to offer. Some of the benefits of pre-cast building solutions include high structural quality, and reduced weight – thus leading to reduced loading and therefore smaller (cost-effective) members. Besides this, pre-cast concrete products can be manufactured in a controlled environment thus leading to consistent quality standards, and the ability to test and innovate. For example, the grade of concrete can be controlled and batch tested before delivery to a project site.
Precast concrete can also be cast in a variety of shapes – both conventional and unconventional. Reinforced concrete can further be pre-stressed before being taken to a construction site, with fast installation times. Note that in this article, we’ll focus on structural solutions such as beams, wall panels, and slabs, as opposed to non-structural precast solutions such as curbs, gutters, septic tanks, and paving blocks.
The Complete Range of Pre-Cast Structural Solutions
There are different precast solutions available, ranging from I-beams to box culverts and beam girders. The most common types in the case of residential and commercial developments are:
- Pre-cast structural beams and columns – are designed to carry transverse loads that cause flexure, and can be classified into T-Beams, I-Beams, L-beams, circular, rectangular, and girder beams. Their structural use spans commercial, residential, industrial and even infrastructure works such as dams, bridges, roads, and railways. Beams can further be pre-stressed, meaning that they can be pre-loaded during concrete setting curing to achieve higher structural resilience.
- Pre-cast concrete slabs – Typical in-situ slab depth usually varies from 150 – 250 mm for commercial and residential developments. With a pre-cast slab, this can be reduced to between 100 – 125 mm and can be pushed even further through pre-stressing. Pre-cast slabs can also be hung on steel frames in high-rises, leading to quick build times and lower structural weight. Prestressed hollow core slabs are voided slabs usually made of prestressed concrete, ideal for constructing multistorey and high-rise structures. Note here that precast staircases are also taken as part of precast concrete slabs.
Waffle slabs – A waffle slab is a two-way joist slab made up of pods that create ribs on its underside. They are preferred for long spans where an increased column span is desirable, for example, buildings in the industrial, hospitality, and education sectors.
- Load-bearing external walls – These types of walls are used to support the load of the structural elements transmitting above them, thus they reduce the need for columns and beams.
- Pre-cast foundation footings – these are usually reinforced.
- Pre-cast joists – These are beam elements that are essentially built like a truss, thus providing a much stronger shape capable of carrying loads over long spans. They can be used in roof, ground flooring, and bridge systems.
- Pre-cast water structures solutions – These include precast storm water drains, precast box culverts, and precast septic tanks.
Pre-Cast Building Solutions in Kenya
The pre-cast building industry in Kenya isn’t quite well documented. Quick research reveals that most companies in Kenya focus on non-structural precast solutions. However, we did manage to unearth a few companies doing groundbreaking work in the precast structures sector.
1. EcoConcrete ltd
This company manufactures precast beams and block concrete flooring. It offers more control over the build process and is ideal for building in remote and waterlogged areas. The beam-&-block system is a suspended concrete floor that is supported by external walls.
Image Source: Beam-&-Block Flooring from EcoConcrete Solutions
2. Global Precast Panels Ltd
This company specializes in the production of precast concrete panels and the construction of prefabricated homes and structures. Its solutions include precast concrete slabs, columns, H-beams, wall panels, channel sections, and pre-fab homes.
Image source: Global Precast Panels Ltd
3. Neulandt
Neulandt is an Austrian company that has recently set up shop in Sierra Leone, Kenya, and Rwanda to provide precast solutions through its portable precast plant. The technology enables the simultaneous optimization of construction time, quality, and cost.
Image source: Neulandt pre-cast building under construction
4. Boleyn Magic Wall Panel Limited
This is a Chinese company that with a precast housing plant in Kajiado County. The company produces wall panels, hollow-core slabs for flooring/roofing, columns, and prestressed beams.
