The hygrothermal transfer is very important for the design of a building envelope for thermal comfort and economic and energy analysis of the building envelope. The applications of various materials in building envelope have been studied... more
The hygrothermal transfer is very important for the design of a building envelope for thermal comfort and economic and energy analysis of the building envelope. The applications of various materials in building envelope have been studied extensively. The study presents several models for the hygrothermal transfer for various building walls. Several energy and mass conservation equations with different boundary conditions and input considerations were presented in this paper for concrete, bricks and wooden walls. The effect of hysteresis was ignored in developing most model equations, while few considered flow pattern of fluid through the wall surfaces. Due to the flexibility of Luikov models, it formed the basis for modelling the coupled heat and mass transfer for porous material independent of hygroscopic nature with different boundary conditions defined according to the geometry and orientations. The influence of type of wall, orientation, thickness, the density of the material an...
Concrete interacts with substances within its environment. These interactions often have significant effects on the properties of concrete made from ordinary Portland cement. The study assesses the effects of oil spillage contaminated... more
Concrete interacts with substances within its environment. These interactions often have significant effects on the properties of concrete made from ordinary Portland cement. The study assesses the effects of oil spillage contaminated water on the performance of concrete in spillage and flaring prone communities in Akwa Ibom State. The result of the physiochemical analysis of the crude oil contaminated water sourced from the study area indicated an acidic medium with acidity index of 4.77, a Ph value of 5.3, turbidity of 0.6 and it also contained Tetraoxosulphate (vi) acid (H 2 SO 4 ) of 0.0116 mg/l andTrioxonitrate (v) acid HNO 3 of 0.1905 mg/l. Concrete specimens were prepared to 1: 2: 4 mix using a water to cement ratio of 0.55 and cured in the contaminated water for 3, 7, 14, 21 and 28 days. The results obtained indicated a reduction in the compressive and flexural strength with 15% and 8% for 3days and 36% and 20% for 28days curing ages respectively, these reductions in strengt...
Shear provisions in codes are based on empirical equations derived from experimental test results without any rational theory to explain its behavior. Some of these expressions, for example BS 8110, ACI 318 and Eurocode 2 takes into... more
Shear provisions in codes are based on empirical equations derived from experimental test results without any rational theory to explain its behavior. Some of these expressions, for example BS 8110, ACI 318 and Eurocode 2 takes into account the effect of reinforcement ratio, effective depth and concrete compressive strength while Canadian code considers the shear strength to be a function of concrete compressive strength only. The new Model code 2010 considers the shear strength of beams as a function of longitudinal strain in the web. This brings about disparity in shear strength prediction from different codes. This paper examines the accuracy of shear strength predictions in beams without shear reinforcement. The study involves a comparative analysis of shear strength predictions from five different codes: BS 8110, Eurocode 2, Canadian code, ACI code 318 and Model code 2010. A total of 435 experimental test results from database of shear critical beams in literature were used for...
Shear provisions in codes are based on empirical equations derived from experimental test results without any rational theory to explain its behavior. Some of these expressions, for example BS 8110, ACI 318 and Eurocode 2 takes into... more
Shear provisions in codes are based on empirical equations derived from experimental test results without any rational theory to explain its behavior. Some of these expressions, for example BS 8110, ACI 318 and Eurocode 2 takes into account the effect of reinforcement ratio, effective depth and concrete compressive strength while Canadian code considers the shear strength to be a function of concrete compressive strength only. The new Model code 2010 considers the shear strength of beams as a function of longitudinal strain in the web. This brings about disparity in shear strength prediction from different codes. This paper examines the accuracy of shear strength predictions in beams without shear reinforcement. The study involves a comparative analysis of shear strength predictions from five different codes: BS 8110, Eurocode 2, Canadian code, ACI code 318 and Model code 2010. A total of 435 experimental test results from database of shear critical beams in literature were used for...
The hygrothermal transfer is very important for the design of a building envelope for thermal comfort and economic and energy analysis of the building envelope. The applications of various materials in building envelope have been studied... more
The hygrothermal transfer is very important for the design of a building envelope for thermal comfort and economic and energy analysis of the building envelope. The applications of various materials in building envelope have been studied extensively. The study presents several models for the hygrothermal transfer for various building walls. Several energy and mass conservation equations with different boundary conditions and input considerations were presented in this paper for concrete, bricks and wooden walls. The effect of hysteresis was ignored in developing most model equations, while few considered flow pattern of fluid through the wall surfaces. Due to the flexibility of Luikov models, it formed the basis for modelling the coupled heat and mass transfer for porous material independent of hygroscopic nature with different boundary conditions defined according to the geometry and orientations. The influence of type of wall, orientation, thickness, the density of the material an...
In this experimental study, compressive strength and resistance to sodium sulphate attack of concrete incorporating recycled ceramic tiles (RCT) as fine aggregate were investigated. RCT was used as partial replacement for river sand at... more
In this experimental study, compressive strength and resistance to sodium sulphate attack of concrete incorporating recycled ceramic tiles (RCT) as fine aggregate were investigated. RCT was used as partial replacement for river sand at four levels (0%, 33%, 66%, 100%). Samples for sulphate resistance tests were immersed in 5% Na2SO4 solution for 180 days after they had been cured under water for 28 days, and were monitored for change in physical appearance, mass change and loss of compressive strength. From experimental results, RCT was found to be capable of producing light weight concrete compared to river sand. The results showed increase in compressive strength as the level of RCT content increased. On resistance to sulphate attack, sodium sulphate seems not to attack C-S-H bond which is produced in excess in RCT concrete, rather it attacks calcium hydroxide and calcium aluminate which are produced in equal amounts for both RCT and control samples. Hence, RCT might not play much...
This study comparatively investigated the strength characteristics and workability performance of partial replacement of natural fine aggregate with waste glass particles and iron filings in concrete production. Fine aggregate was... more
This study comparatively investigated the strength characteristics and workability performance of partial
replacement of natural fine aggregate with waste glass particles and iron filings in concrete production. Fine
aggregate was replaced with 0%, 5%, 10%, 15%, 20%, and 25% of waste glass particles and iron filings
respectively at a water-cement ratio of 0.55. The result indicated that an increase in percentage replacement of
iron filings reduced the slump value and workability of the concrete, while the increase in the percentage content
of glass particles increased its slump value and workability. The result showed that concrete with 20%
replacement of sand by iron filing and waste glass particles attained the optimum strength. Furthermore, concrete samples containing glass particles exhibited a steady increase in flexural strength at all replacement levels.
The use of iron filings and glass particles in the production of concrete will enhance preservation of natural
resources and waste management
