Comparison Of Locally Excavated Sand With River Sand In Terms Of Strength In Sandcrete Blocks

Project Abstract

Sand is a major component in construction works, especially in the production of concrete and sandcrete blocks. The sourcing of quality sand is essential to ensure the structural integrity and durability of buildings. This study investigates the comparison of locally excavated sand with river sand in terms of strength in sandcrete blocks. The research methodology involved the collection of sand samples from local excavation sites and riverbanks. These samples were then tested for their physical properties and used in the production of sandcrete blocks for compressive strength testing. The results of the study indicate that locally excavated sand and river sand have different physical properties that can impact the strength of sandcrete blocks. Locally excavated sand tends to have more impurities and higher percentages of fines compared to river sand. These differences can affect the workability and strength of the sandcrete blocks. The compressive strength tests revealed that sandcrete blocks made with river sand generally exhibited higher strengths compared to those made with locally excavated sand. Factors such as particle size distribution, shape, and texture play a significant role in the strength of sandcrete blocks. River sand, which is naturally weathered and rounded, tends to have better particle packing and interlocking, resulting in higher strength properties. In contrast, locally excavated sand may contain angular particles and a higher percentage of fines, leading to reduced strength and durability in sandcrete blocks. The findings of this study highlight the importance of using quality sand in construction materials to ensure the structural performance of buildings. While locally excavated sand may be more readily available and cost-effective, builders and contractors should consider the potential trade-offs in terms of strength and durability when choosing between locally excavated sand and river sand for sandcrete block production. In conclusion, the comparison of locally excavated sand with river sand in terms of strength in sandcrete blocks demonstrates the impact of sand quality on the structural properties of construction materials. Builders and engineers should carefully evaluate the physical properties of sand sources and conduct testing to determine the most suitable sand for achieving the desired strength and durability in sandcrete block production.

Project Overview

INTRODUCTIONThis research work means to determine the different properties of sandcastle blocks moulded with a locally excavated sand, in terms of compressive strength, durability and cost and economic importance, and that of River Sand. And after, compare the two strengths of the sandcrete which will help in recommending the right give the desired strength for the designed strength for a particular purpose.NSUDE as case study, Nsude is in Udi, Enugu west, Enugu State.1.1 BACKGROUND OF THE STUDYSandcrete is a yellow-white building material made from a binder (Portland cement), sand in a ratio of circa 1:8, and water. Sometime other ingredients may be added to reduce the amount of Portland cement such as “pozzolanas and rice husk ash”. Sandcrete is similar but weaker than mortan for which the ratio is 1:5.Sandcrete is usually used as hollow rectangular blocks similar to concrete masonry units, often 45cm (18”) wide, 15cm (5.9”) thick and 30cm (12”) with hollows that run from top to bottom and occupy around one third of the volume of the block.1.2 STRENGTH AND USAGEThe final compressive strength of sandcrete can be as high as 4.6N/mm2 which is much less than concrete’s 40N/mm2. Sandcrete is unsuitable for load-bearing columns, and is mainly used forwalling of a house–     making a fence–     Septic tank and soak away tank’s–     Building a generator’s house.In Nigeria, measured strength of commercial available sandcrete blocks was found to be between 0.5 and 1N/mm2, which is well below the 3.5N/mm2 that is legally required. This development may be due to the need of the manufacturers to keep the price low, and since the main cost-factor is the Portland cement, they reduce that, which results in a block that starts behaving more like loose sand.1.3 SANDCRETE BLOCK SIZESThey are many different types of blocks used in modern building, they include:

• 9” hollow blocks (450mmx225mmx225mm)
• 6” hollow blocks (450mmx150mmx225mm)
• 6” solid blocks (450mmx150mmx225mm)
• 5” solid blocks (450mmx125mmx225mm)
• 9” solid blocks (450mmx225mmx225mm)

1.4 CONSTITUENT MATERIALS OF SANDCRETE BLOCKSThese include cement, fine aggregate (sharp sand) and water.1.4.1 CEMENTThis refers to any adhesive and the material used in connection with block and it is referred to as “hydraulic cement” because the setting and hardening depends on the preserve of water. The cement widely used in civil work is called “Ordinary Portland Cement”.1.4.2     FINE AGGREGATEThe two major types of sand used are white and coloured sand. The sand were not free from materials such as dust, silt, tree roots etc. The sources of sand include pits, rivers and sea.1.4.3     WATERAny type of water available can be used to mould sandcrete blocks. This includes water from stream, rivers, boreholes etc.1.5 STATEMENT OF THE PROBLEMApart from bad mixing ratios, which happen even some sandcrete blocksproducers add more yield of blocks, some other things can cause blocks to be in bad condition which can affect the quality of the sandcrete produced.1.5.1     USING OF BAD CEMENTDue to the prevailingadverse economic conditions, some sandcrete block makers tend to go for very cheap cement which may not have the required quality to bind a solid block. These block break soon after they are made. Some cement sellers who had cement keptin stock for so long sell it at give away price to the sandcrete block makers if the notice that the quality of the cement has detoriated.1.5.2 RE-BAG CEMENTAnother thing to note with cement is that some cement sellers re-bag cement, removing some quantity of cement or put low quality cement product in a bag of a high quality and trust cement brand. Theration you thought you are using to produce a given quality has been compromised and it will produce a low quality block that can easily break even before it is being used for the project.1.6 THE OBJECTIVE OF THE STUDY

• This project research will help us to understand the different strength of sandcrete blocks produced with locally excavated sand and River sand.
• This will also help to know the properties of Nsude sand after laboratory test has been carried out.
• This will help us in determining the moulding methods and properties of sandcrete blocks. These properties are determined by the ratio of block constituents such as cement, water and sand.

1.7 SCOPE OF THE STUDYThe scope of this project work is limited to obtaining the comparison of locally excavated sand with River sand in terms of strength in sandcrete blocks.(Nsude as case study).1.8 SIGNIFICANCE OF THE STUDY

1. To help us understand the strength of sandcrete blocks produced with locally excavated sand and River sand in Nsude.
2. To help us determine the properties of Nsude sand after carrying out laboratory test