Review of Sustainability in Self Compacting Concrete: the use of waste and mineral additives as supplementary cementitious material and aggregate.

Concrete is one of the commonly used construction materials, but there is a need to develop a new and sustainable technology to make concrete more affordable. With the advancement in technology, concrete was no longer seen as a three entity (binder, aggregate, and water). The unique workability properties of SCC make it unique in the concrete industry. This review assessed the materials, strength, rheological properties of agricultural waste, industrial waste and mineral additives in SCC production. The effect of the utilization of these additives and replacements on structural, mechanical and rheological properties of SCC was espoused. The review revealed that the use of both industrial and agricultural waste enhances the strength properties of SCC. Additionally, the use of agricultural waste improves the rheological properties of fresh concrete. The utilization of expansive material should be discouraged in SCC production. The review revealed that SCC developments ensure a good balance between deformability and stability. It was therefore recommended that SCC should be utilized in pavement construction, particularly when high axle load is expected

Characterization of ceramic waste aggregate concrete

There is a growing interest in using waste materials such as ceramics as alternative aggregate materials for construction. While other ceramic product wastes such as sanitary wares and electrical insulators have been extensively investigated, not much findings are available on ceramic wall and floor tiles wastes. Thus, the current study focuses on the mechanical characterization of waste ceramic wall and floor tiles aggregate concrete. Ceramic wastes sourced from construction and demolition wastes were separated from other debris and crushed using a quarry metal hammer. Ceramic tiles were sieved into fine and coarse aggregates in line with standards. Other materials used were gravel, river sand, cement and potable water. Workability of the fresh concrete was checked through slump test, and concrete cubes of 150 mm dimensions and cylinders of 100 mm � 200 mm were cast in the laboratory. After 24 h of casting, the concrete samples were demolded and were cured by immersion in water tank at temperature of 22 �C. The compressive and split-tensile strengths of the hardened concrete samples were determined after curing them for 3, 7, 14 and 28 days. Results showed that both the compressive strength and split tensile strength increased appreciably with the curing age than the conventional concrete

Effect of Common Salt on the Engineering Properties of Expansive Soil

This paper investigated the effect of common salt on some geotechnical properties of expansive soil for highway pavement (subgrade) works. In this study, engineering properties including; Natural water content, Atterberg limits, specific gravity, compaction, free swell index, unconfined compressive strength, soaked and unsoaked California bearing ratio were determined in the laboratory and their behavior on stabilizing with various percentages of sodium chloride (0, 0.5, 1.0, 1.5. 2.0 and 2.5) investigated. From the study, plastic limit, liquid limit, plasticity index, linear shrinkage, specific gravity, free swell index and optimum water content values of the stabilized soil reduced, while the maximum dry density, California bearing ratio and unconfined compressive strength values increased. The highest reduction percentages of 60.42 % (131 to 51.85 %), 42.86 % (50.00 to 28.57 %), 71.26 % (81.00 to 23.28 %), 66.64 % (15.11 to 5.04 %), 83.43 % (115.00 to 19.05 %), and 28.57 % (28.00 to 20.00 %) in liquid limit, plastic limit, plasticity index, linear shrinkage, free swell index and optimum water content respectively; and maximum percentage increase of 11.38 % (1.67 to 1.86 g/m3 ,on maximum dry density), 31.78 % (29.20 to 38.48 %, on unsoaked CBR), 257.67 % (4.3 to 15.38 %, on soaked CBR), and 26.98 % ( 67.86 to 86.17 kN/m2 on unconfined compressive strength) were obtained on treatment of the soil with 1.5 % common salt by weight. Treatment of the soil with common salt has thus reduced its swelling potential and increased the strength

Mechanical Properties of Dehydroxylated Kaolinitic Clay in Self-Compacting Concrete for Pavement Construction

The high increase in the cost of cement has led to a reduction in concrete production in most developing and under-developed countries. Therefore, the need for a sustainable and cost-effective substitute for cement is necessary. This research focused on the application of dehydroxylated kaolinitic clay in the production of self-compacting concrete for pavement construction. The elemental and oxide composition of the cementitious material (cement and metakaolin) was assessed using atomic absorption spectrometry and a scanning electron microscope was used to determine the particle geometry. Six mixtures of SCC with 0%, 5%, 10%, 15%, 20% and 25% metakaolin replacement were incorporated into this concrete mix. The passing ability,segregation ability and the flowing ability of the fresh concrete were assessed. The strength properties of the various mixtures (compressive and flexural) of the samples were also assessed at 3, 7, 14, and 28 days. The rheological properties showed that the addition of dehydroxylated kaolinitic clay higher than 10% showed poor rheology. However, percentages greater than 15% gave a reduction in compressive strength and flexural strength. In a bid to encourage sustainability in road construction and adopt the use of eco-friendly material, metakaolin is a viable material

Pavement construction using self-compacting concrete: Mechanical properties

This experimental study assessed the strength properties of some selected Portland limestone cement for self-compacting concrete in pavement construction. Self-compacting concrete offers many advantages in the construction world but its utilization in pavement construction is low. To achieve the aim of this research, four brands of grades (42.5 and 32.5) of the cement were used. Cement brands A, B, C and D were used in SCC samples tagged as SCC 1, 2, 3 and 4 respectively. To this end, rheological tests were carried out using the L-Box, V-Funnel and slump cone. Additionally, mechanical properties (compressive, split tensile and flexural strength) of the hardened concrete were evaluated. The compressive and flexural tests were determined at 3, 7, 14, 21 and 28, 56 and 91 days of curing. SCC 4 with Brand D showed the highest strength at 3 days but had the lowest at 28 days and 91 days. However, SCC 1 with brand A showed the highest strength at maturity. Additionally, the result showed that the percentage difference in the compressive strength of the SCC 1 and the other mixes were 27.6%, 27.7% and 40.7% while 18.1%, 27.5% and 42.1% increment was recorded for the flexural strength of SCC 1, SCC 2, and SCC 3 respectively. However, SCC 4 had the best rheological properties, though the lowest strength. A positive strong correlation was recorded for the mechanical properties of the SCC mixtures. Moreover, the relationship between the mechanical properties and age followed a logarithmic trend with R2 value that ranges from 0.86 to 0.977 which established the robustness. Ultimately, the result revealed that SCC 1 with brand A proved to be the most suitable for SCC in rigid pavement construction

Self-compacting concrete in pavement construction: Strength grouping of some selected brands of cements

This paper investigates strength properties of some selected cement brands for self-compacting concrete application in pavement construction. Three brands each of Portland limestone cement grades, CEM II/A-L 42.5 (Brand A), CEM II/B-L 32.5 (Brand B) and CEM II/B-L 32.5 (Brand C), were used. Rheological test was carried out using the L-Box, V-Funnel and slump cone while compressivegas emissions from the building sector. These systems require high investments which are returned through the heat sales. Due to the changed climate conditions and building renovation policies, heat demand in the future could decreas

Novel concrete mixture using silica rich aggregates: workability, strength and microstructural properties

The persistent reliance on traditional construction materials is of no gain to the future generation. The rate at which the natural aggregate sources are explored is alarming, and as a result, the threat of depletion of the natural materials has inspired interest in sustainable construction materials, focusing on construction and demolition wastes and local materials. In this study, an experimental insight on modified concrete, based on workability, strength and microstructural properties, is provided, in an attempt to ascertain the suitability of silica-rich aggregates (ceramic industry wastes and laterite) as a replacement for conventional fine and coarse aggregates. Various mix proportions were considered, and material batching was done by weight for concrete casting. The workability test, using slump, indicates that the flowability of the modified concrete mixes is achievable at a water-binder ratio of 0.6. The strength properties of the concrete increased with the increasing ceramic substitution for granite while increasing laterite content beyond 10% negates the strength gain by the concrete. A concrete mix containing 90% ceramic fine and 10% laterite, as fine aggregate, and 100% of cement and ceramic coarse, as binder and coarse aggregate, respectively, gave higher compressive strength (22.5 MPa), and split-tensile strength (3.6 MPa), and these results were found as comparable to the conventional concrete

Synergistic Effect of Cement and Mucilage of Optuntia ficus indicaCladodes on the Strength Properties of Lateritic Soil

In a bid to reduce the cost of pavement construction and the environmental impact of using cement as a conventional stabilizer, there is a need for a green alternative. The use of mucilage of Optuntia ficus indica cladodes (MOFIC) which contains several amino acids and sugars was used in improving the strength properties of cement stabilized lateritic soil. The parameters tested were atterberg limits, compaction characteristics (optimum moisture content and maximum dry density), California bearing ratio (CBR) and the UCS. The addition of (cement + MOFIC) to the cement stabilized sample reduced the plasticity index which improved from a subgrade to a subbase material. Furthermore, the CBR value of 76 an

14 Molar Concentrations of Alkali-Activated Geopolymer Concrete

The increase in construction activities due to economic and population growth has led to the higher demand and utilization of cement. But cement production leads to the pollution of the environment. Consequently, this study examines the utilization of both ground granulated blast furnace slag (GGBFS) and corncob ash (CCA) as source materials in the production of geopolymer concrete (GPC). GGBFS was replaced by CCA in 0%, 20%, 40%, 60%, 80% and 100% respectively using Grade 30 (M30) mix design proportion. Alkaline liquids were prepared to obtain 14 molar concentrations and used to activate the source materials. Slump, density and compressive strength of GPC were determined and compared with Portland cement concrete (PCC). The research findings indicate that GPC has higher compressive strength than PCC. Based on the relationship between the compressive strength and the density, a model equation is established. And the equation is used to predict the compressive strength of GPC with respect to the density. Reprocessing of CCA and GBFS as emerging low-carbon footprints appears to be a feasible solution to the problem of environmental pollutio

Hydration mechanism and strength properties of recycled aggregate concrete made using ceramic blended cement

A pozzolanic material ordinarily contains high amounts of siliceous or aluminous components, but has no cementitious property until when it reacts with calcium hydroxide, that is available in cement, in the presence of moisture. The present study evaluates the pozzolanicity of ceramic tile powder and its effect on both hydration mechanism and strength property of recycled aggregate concrete. It was seen that ceramic floor and wall tiles sourced from construction and demolition wastes, contain high silica and alumina oxides, which evidently showcased its pozzolanicity. This was further revealed by the microstructural images of ceramic blended cement. Strength properties of recycled aggregate concrete were enhanced with addition of ceramic powder and ceramic coarse fraction, more than the strength developed in the control concrete. The increased strength was an indication that the interfacial transition zone between the aggregate and blended cement paste enhanced the properties of recycled aggregate concrete (RAC). However, the tensile behavior of RAC was irregular, it initially decreased with 20% ceramic powder addition but it increased when 30% ceramic powder was added. Therefore, ceramic power derived from wall and floor tiles can be used as partial replacement for cement in recycled aggregate concret