Nkey Henry Nkey *
The production of paving blocks was developed after post war Europe reconstruction, in the late 1940’s that saw the revitalisation of ancient techniques of pavement production, following the introduction of modern and cheaply mass-produced concrete paving blocks. This development grew largely out of the exigencies of reconstruction after the war because of the advantages offered against other types of pavements and there was nothing to hinder the use from spreading beyond Europe. They were introduced in North America by early 1970’s and this method of paving became widely accepted with 400 million m2 produced and installed yearly [27, 39]. This type of paving blocks were embraced for pavements because of aesthetics and patterns offered as well as high structural strength, slip resistance, and durability. Most paving blocks were initially used for commercial and residential areas. But nowadays there are thousands of successful projects design and constructed with paving blocks that have proven the ability to low maintenance and high resistance to deterioration from moisture, point loads, abrasive actions, resistant to skid and petrochemicals. The projects have widen the use of paving blocks for pavements of high traffic loads [27, 39].
They are produced from high quality concrete composed of a combination of Portland cement, coarse and fine aggregate with sufficient water to produce zero-slump concrete, moulded in specialised equipment under vibration and extreme pressure. Admixtures are sometimes added to increase various engineering properties and reduce likelihood of efflorescence while decreasing water absorption [11, 31]. They are precast solid products of various sizes and shapes to interlock with adjacent blocks.
Labour basoed technology as in my last research “design and construction of interlocking pavements through labour based technology” is an approach that uses a mixture of labur/equipment giving priority to labour, while supplementing it with appropriate equipment where necessary, integrating quality and cost. This way infrastructures are constructed to standards with minimum cost, where those employed are treated with dignity and respect and are paid fair wages including opportunities for personal development and social integration [37, 38]. However, producing paving blocks through this approach is cost effective and a sustainable approach that utilizes local resources while producing quality products. This approach leads to the creation of employment, contributes to poverty alleviation and economic growth, promotes community participation including infrastructure ownership and can incorporate environmental friendly practices such as use of high quality local materials while minimizing waste. The promotion of this technology provides many advantages to developing countries, since they have limited resources for infrastructure development and maintenance through adoption, where the technology and economy are able to support [37, 38].
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- Purpose Statement
The purpose statement of this study is to explore how paving blocks are produced through labour-based technology. This approach can be a perfect solution for solving the problems of infrastructure deficit in developing countries. It can contribute immensely to knowledge transfer, protection of infrastructure against vandalism and early damage and sustainable development. It also discusses the different processes and technics for moulding paving blocks.
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- Main objective
The main objective is to understand how paving blocks are produced through labour-based technology and how it stands to benefit stakeholders and the beneficiaries. The most important aspect involves understanding the characteristics of materials used and quality control. Having this in mind, knowing the moulding of paving blocks is affected by several parameters directly influencing quality. The labour based technology can be a perfect tool to promote sustainable development especially in developing countries.
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- Limitations and challenges of labour based technology
The labour based technology emphasizes on the use of labour and skills in the construction industry, but do have several limitations and challenges, such as:
- Labour based technology requires a large work force which can be time consuming and costly.
- Labour based technology demands skilled labour force, which can be in short supply especially in areas with limited training programs.
- Labour based technology can be less productive than equipment based, particularly for large scale projects.
- Ensuring consistent quality can be challenging, since it relies on individual workers skills and attention to details.
- Labour based technology can be difficult to scale up for large projects.
- While labour based technology can be cost effective for small scale projects, it can become expensive for large projects due to labour cost.
- Labour based technology can be slow, especially for projects requiring high level of precision or details.
- Labour based technology can be weather dependent, which can lead to delays and disruptions.
- Labour based technology can pose safety risks, especially if workers are not trained or equipped.
- Labour based technology may not be as innovative as equipment technology, which can limit its potential for reforms and deficiency gains.
- Access to quality materials may be limited in some areas.
It is very important to overcome these challenges before engaging this technology for the implementation of any project by applying essential rules, in the following ways:
- Investing in worker training and development programs.
- Implementing efficient project management and planning techniques.
- Using labour based technology in conjunction with machine based technology.
- Focus on small scale projects that can benefit from labour based technology.
- Develop innovative solutions that combine labour based approach with modern materials and techniques.
- MATERIALS FOR PRODUCING PAVING BLOCKS
Good quality concrete paving blocks are manufactured from a homogeneous mix of cement, fine and coarse aggregates. When mixed together in their right proportions, a dense material is produced. The addition of water to the mix reacts chemically with cement enabling it to harden and makes the complete mix easy to handle and transport where they are moulded. The fine aggregate fills up voids between the paste and the coarse aggregates, acts as fillers, providing most of the bulk and the strength of concrete, while the cement binds all individual particles together. Admixtures can also be used to increase engineering properties as necessary [9, 11, 12, 31, 32]. Here below is a description of the materials to be used for the purpose and must conform to technical specifications:
10.5281/zenodo.15020052