Suitability of Laterite Fines as a Partial Replacement for Sand in the Production of Sandcrete Bricks
The provision of affordable housing units from indigenous building materials has been the focus of most researchers in recent times. This paper focuses on the utilisation of laterite fines as replacement for sand in the production of sandcrete bricks as masonry units. With a mix ratio and a water/cement ratio of 1:6 and 0.50 respectively, batches with 0% (control specimens), 10%, 20%, 30%, 40% and 50% laterite fines replacing the sand were adopted in this study. In all, 96 bricks were cast, tested and compared with those of conventional sandcrete bricks (control specimens). Tests studied were density, compressive strengths (wet and dry) and water absorption. Data results revealed that the laterite fines used could satisfactorily replace the sand up to 30% for the production of structural masonry units even though bricks need to be protected when used in waterlogged areas or below ground level.
Study on Strength of Concrete by Partial Replacement of Fine Aggregate with M-Sand and Laterite with Super plasticizers
This paper presents a study conducted to determine the suitability of partial replacement of sand with laterite soil and manufactured sand in M20 grade concrete. The first phase is to find the maximum percentage of sand can replace with lateritic soil and manufactured sand for both M20 grade concrete. Concrete mixes containing 0,10,20,30, 40% sand replacement levels were cast, with super plasticizer. Split tensile strength, compressive strength test and flexural strength were conducted in accordance to the existing standard. Results show maximum of 20% replacement levels of sand by laterite attained workable concrete with satisfactory strength beyond that lateritic concrete is not workable And 40% replacement of sand by manufactured sand shows maximum strength. Mix proportion is taken as 1:1.5:3 based on the design result. KeywordsLaterite, Manufactured sand, Fine aggregates, Super plasticizers.
Some Hydraulic, Mechanical, and Physical Characteristics of Three Types of Compressed Earth Blocks
Three types of compressed earth blocks (CEB) were processed to carry out a comparative
study on some of their hydraulic, mechanical, and physical characteristics. They were namely
the unstabilized CEB, the partially stabilized CEB, and the fully stabilized CEB. The partial
stabilization of the CEB was achieved by wrapping its unstabilized earthen inner part all
around with a stabilized earthen crown. Soil stabilization was done using Portland cement.
Levels of cement mixed with soil were 0, 6, 8, and 10%. Two wrapping crown thicknesses
were tested: they were 0.75 cm and 2.25 cm. Mechanical tests consisted of running the
compressive and the flexural strengths on CEBs. Physical and hydraulic properties evaluated
were respectively their abrasion loss of matter and water absorption.
Results show that the fully stabilized CEB performed better in regard to all the tests. The two
remaining types of CEB displayed similar mechanical characteristics. However, abrasion loss
of matter of the partially stabilized CEB was lower than that of unstabilized CEB. In addition,
unstabilized CEB did not sustain the water absorption test.
This investigation shows that the partially stabilized CEB with 2.25 cm crown thickness is
mechanically safe and meets the requirements for earthen construction. Therefore it might be
recommended to the earthen construction industry as an interesting alternative for the fully
stabilized CEB since its processing requires a lesser amount of cement.