58 research outputs found
Performance of Self Compacting Concrete Incorporating Ground Granulated Blast furnace Slag and Metakaolin
The experimental study of two supplementary cementitious material on self-compacting
concrete was investigated. Three mixes were designed, the control mix without the supplementary
cementitious material, second mix with metakaolin (MK) and third mix with ground granulated blast
furnace slag (GGBFS) both at 5, 10, 15, 20 and 25% respectively. After each mix preparation,
workability test was carried out and specimens of the three mixes were cast and cured in water for 7,
14, 21 and 28 days respectively. Tests on hardened concrete were carried out to know the
compressive strength of the three-mix designs. The test results showed that a replacement of 5% of
both admixtures GGBFS and Mk increased in the compressive strength compared to the control mix.
Also observed was the presence of mineral admixtures that had a significant on the strength loss due
to the sodium, calcium and magnesium sulphate attack. The best resistance was obtained for 5% MK
and GGBFS at 28 days curing
He’s polynomials method for analytical solutions of telegraph equation
In this paper, He’s polynomials solution method (HPSM) is fully utilized for solving
telegraph equation. The proposed HPSM is technically presented and applied to homogeneous
linear form the telegraph equation. The results are expressed in closed form with good
agreement compared to those in literature thereby attesting to the efficiency and reliability of
the method as proposed. The HPSM remarked to be less time consuming with high level of
accuracy. As such, it can serve as alternative to other methods
The use of rice husk ash as admixture in producing selfcompacting concrete
Admixtures are incorporated into concrete in today’s world in order to achieve variety
of goals. This research study the use of rice husk ash as an admixture in producing selfcompacting
concrete. The rice husk ash is varied in different percentages (5, 10, 15,
20, 25 and 30%) as partial replacement for ordinary Portland cement (OPC) to know if
it improves the properties of fresh and hardened properties of the self-compacting
concrete. The superplasticizer used was conplast SP 430 and the water cement ratio
0.35 was kept constant throughout all mix. Rice husk ash is a good super-pozzolan
which is used to make special concrete mixes, in which the slump Flow, T50cm slump,
V-funnel and the L-box test was used to test for the workability of the fresh concrete
mix and the compressive strength of each mix was tested to know the specific strength
of each self-compacting mix with varying percentage of rice husk ash at 7, 14 and 28
days of curing
Interaction assessment and optimal design of composite action of plastered typha strawbale
The concept design of the typha strawbale masonry came up as a result of the urgent demand for a means of constructing sustainable buildings, both in rural and urban settlement, not only suitable for dwellers but for keeping farm products by structures that will respond to the environmental eco-system, coupled with the fact that such structures are also affordable, durable and easy to maintain during their service period. The effects of contact between plaster and the stacked strawbale of a masonry needs to be established and design optimization for durability and stability of the masonry be obtained. The assessment will involve the application of plaster materials (cement and natural earth) to the wall specimen panels. Past works have shown that plastered strawbale walls have adequate resistance against the appropriate vertical loads, and further showed that the earth plaster can bear higher stress than the cement plastered straw bale. There is the implication that the collapse or response of the earth-strawbale wall is significantly higher compared to that of cement-strawbale from other straw-based masonries. Therefore the allowable stresses of plastered typha strawbale shall be predicted for their optimum values using SAP2000. The stress stability of each masonry is obtained by analytical model using the best fit variables for the wall height and thickness
Strength Characteristics of Concrete Reinforced With Sugar Cane Bagasse Fibre
This paper examined the strength characteristics of sugar cane Bagasse fibre incorporated into concrete. The Utilization of fibre in concrete production not only solves the problem of disposing this solid waste but helps conserve natural resources. A total of 40 each for cubes, cylinders and beams were cast for this study. The cubes were of dimension 100mm×100mm×100mm, the beams were 500mm×100mm×100mm in cross-section while the cylinders were 100mm in diameter and 200mm long. Five mixes of various strength grades were prepared at varying percentages of 0, 0.5, 0.75, 1.0 and 1.25%. The concrete with no fibre served as control. Conplast SP430MS was used as superplasticiser. Water-cement ratio of 0.5 was maintained for all mixes. The design mix obtained was1:1.7:2.5. Compressive strength, flexural strength, splitting tensile strength were determined at 7, 14, 21 and 28 days of curing
Durability Properties of Palm Oil Fuel Ash Self Compacting Concrete
Self Compacting Concrete (SCC) is a new innovation
in technology that can flow readily into place under its own self
weight and fill corner areas of reinforcement structures without
the need to vibrate and without segregation of its constitute. The
problem of durability of concrete structures due to inadequate
compaction by skilled workers has become a source of concern
globally. The shortage of skilled manpower, noise and vibration
of equipment on construction sites has led to the development of
self compacting concrete. This paper presents an experimental
study on the durability properties of Self Compacting Concrete
with partial placement of Palm Oil Fuel Ash (POFA). Twelve
POFA self-compacting concretes of various strength grades were
designed at varying percentages of 0, 5, 10, 15, 20, 25 and 30%.
The concrete with no placement of ash served as control.
Conplast SP432MS was used as superplasticiser in the mix. The
experiments are carried out by adopting a water-powder ratio of
0.36. Workability of the fresh concrete is determined by using
tests such as: slump flow, T50, V-funnel and L-Box tests. The
durability of concrete is tested by acid resistance, sulphate attack
and saturated water absorption at the age of 14, 28, 56 and 90
days
Utilization of marble dust powder in concrete
The economic costs of construction have become largely unbearable today. In a bid
to mitigate these costs, civil engineering faculties and stakeholders across the world have
endeavoured to produce recyclable and resource saving concrete for construction purposes.
Most of the environmental problems are caused by the deposit of waste to the environments in
which marble shaping is part. Both stone slurry and solid wastes are generated from the marble
stone slurry and with the huge discharge of marble waste locally, emphasizes has been placed
on the reuse of the waste material. This research investigates the utilization of marble dust
powder in concrete, where marble dust at varying percentage (0%, 15%, 25% & 35%) with
replacement by sharp sand was added in M15 grade and water cement ratio 0.50 was kept
constant in the concrete mixes. The quality, performance and reliability of the concrete where
tested by the compressive and split tensile strength of 7, 21, 28 and 56 curing days. The results
of the laboratory work showed that marble dust powder replacement with cement increased in
strength up to 25% for both resistance to compressive load and tensile strength of concret
Effect of various types and sizes of aggregate on selfcompacting concrete
Aggregates play important role in concrete; it serves as Structural fillers which are
used in concrete production. Aggregate sizes, types and gradation are the most important factor
when selecting aggregate. This study examines incorporating different sizes and types of coarse
aggregate. Testing rheology and strength of self-compacting concrete mixes at varying sizes and
different types of coarse aggregate. The various aggregate sizes used in the Various mixes are
10, 12.5 and 20mm, the types of aggregate used are granite, gravel and ceramic tiles and
superplasticizer used is Conplast SP 430 with water cement ratio of 0.45. slump flow test, T50,
L-box and V-funnel test were carried out on the various mix to determine the fresh properties of
the concrete mix. The mechanical properties (compressive, flexural and split tensile strength test)
were conducted on the mixes at different curing age (7, 21 and 28 days). The aggregate size
10mm and granite types had the highest slump flow for the fresh test. It was observed from the
mechanical test 10mm and 12.5mm granite size had a higher strength than gravel and ceramic
tiles
Effect of waste aluminium shavings on the bond characteristics of laterized concrete
The utilization of fibre in concrete production not only solves the problem of disposing this solid waste
but helps conserve natural resources. This study investigated the effect of waste aluminum shavings on
bond strength of laterized concrete. Laterized concrete spliced beams
of 150×250×2150mm150×250×2150mm and 175×275×2300mm175×275×2300mm were
prepared. Fifteen specimens with 16 mm and 20 mm were cast with the addition of aluminium
shavings at varying percentages of 1vol%, 1.5vol% and 2vol%; another ten specimens with 16 mm and
20 mm diameter bars at 0% of aluminium shavings were cast as control. Concrete cubes of number
were prepared, three taken for each set of various percentages of aluminium shavings were used to
determine the concrete strength. It was observed from the analysis that the compressive strength
decreased as the percentage of aluminium shavings increased, while the aluminium shavings increased
the bond between concrete and steel. However, for normal concrete there was an increase in bond
resistance with increase in aluminium shavings. The bond resistance of 16 mm was found to be higher
than that of 20 mm in all the specimens tested
ASSESSMENT OF THE GEOTECHNICAL PROPERTIES OF TERMITE REWORKED SOILS
The determination of the geotechnical properties of inhabited termitaria (termite mounds) from three different
locations in Lagos, Nigeria was carried out. Soil samples were taken at the cores of termitaria and also at 3m of either side
of termitaria. Nine bulk representative soil samples depicting three termitaria soils and six adjacent soil samples were
collected. Some geotechnical properties such as specific gravity, grain size distribution, consistency limits, linear
shrinkage, CBR, and consolidation of the soils were determined. The chemical properties of the termitaria soil as compared
to the adjacent surrounding soil was also analysed. The result showed that the geotechnical properties of termitaria are far
better than the adjacent or surrounding soils. The activity of termites was identified as the primary cause of these
improvements
- …