Push Tests on Innovative Shear Connector for Composite Beam with Cold-formed Steel Section

In this study, experimental tests were conducted to investigate the ductility and strength capacity of new shear connector. Push test specimens were prepared and tested according to EN1994-1-1 standard. The push test specimen consists of two cold-formed steel lipped channel sections oriented back-to-back to form an I-section beam, transverse metal deck and normal concrete slabs grade C25/30. Angle brackets were obtained from the same section of the beam and fastened to the web of steel beam to provide the shear connection. Two shear connectors were tested namely; “SC1” and “SC2” shear connectors. Both shear connectors showed a ductile behavior and had satisfied the ductility requirements of EN1994-1-1 standard. It was concluded that the ductile behavior of shear connectors could enhance the design of composite beam

Methane Gas Hydrate Formation by Using Sodium Dodecyl Sulfate Additives

Gas Hydrates (G. Hyd) such as methane (CH4) hydrates are forming of water molecules in ice-like crystals (lattice shape) with cavities where the methane gas (gust gas) molecules are engaged in, and this process is conducted in a certain condition, mainly in low temperature and high pressure. The objective of the current work is to study the effect of Sodium Dodecyl Sulfate (SDS) additives on Methane gas hydrate performance. Two solutions were prepared. The first solution consists of distilled water (100 ml), methane gas and SDS additives (0.10 g). The second solution consists of same ingredient with seawater (100 ml) instead of distilled water. A stirred tank with 750 psi has been utilized. The highest recovery ratio was 42.15% for distilled water using SDS additives with a pressure cycle duration of 120 minutes. Significant improvement in the hydrate water recovery ratio can be obtained with distilled water and seawater by about 42 % and 15.6% respectively. Generally, SDS additives improve the recovery rate for water in the presence of methane

HCV Infection among Saudi Population: High Prevalence of Genotype 4 and Increased Viral Clearance Rate

HCV is a major etiological agent of liver disease with a high rate of chronic evolution. The virus possesses 6 genotypes with many subtypes. The rate of spontaneous clearance among HCV infected individuals denotes a genetic determinant factor. The current study was designed in order to estimate the rate of HCV infection and ratio of virus clearance among a group of infected patients in Saudi Arabia from 2008 to 2011. It was additionally designed to determine the genotypes of the HCV in persistently infected patients. HCV seroprevalence was conducted on a total of 15,323 individuals. Seropositive individuals were tested by Cobas AmpliPrep/Cobas TaqMan HCV assay to determine the ratio of persistently infected patients to those who showed spontaneous viral clearance. HCV genotyping on random samples from persistently infected patients were conducted based on the differences in the 5′untranslated region (5′UTR). Anti-HCV antibodies were detected in 7.3% of the totally examined sera. A high percentage of the HCV infected individuals experienced virus clearance (48.4%). HCV genotyping revealed the presence of genotypes 1 and 4, the latter represented 97.6% of the tested strains. Evidences of the widespread of the HCV genotype 4 and a high rate of HCV virus clearance were found in Saudi Arabia

Towards light-weight composite construction: innovative shear connector for composite beams

Introducing low cost housing is one of the challenges face civil engineers now-days. Using lightweight construction materials i.e. cold formed steel sections is an alternate solution to overcome the challenge. In this study, a lightweight composite beam was introduced. It consists of cold formed steel section and profiled concrete slab. Experimental push tests were conducted to investigate the ductility and strength capacities of new and innovative shear connectors. The shear connectors were easy to form and give advantages to speed up the fabrication process of the proposed composite beam. The shear connectors showed large deformation and strength capacities. It is concluded that the proposed shear connectors could be used for lightweight composite beams

Palm Oil Fuel Ash: Promising supplementary cementing materials

Palm Oil Fuel Ash (POFA) is by-product obtained by burning of fibers, shells and empty fruit bunches as fuel in palm oil mill boilers. In this investigation, three ashes were collected from different palm oil mills around Malaysia and namely CAPOFA, ALPOFA and KTPOFA. The ashes were ground to 45 µm before replace 20% by weight of cement in concrete and mortar. The compressive strength of concretes containing POFA was tested at ages of 7, 28 and 90 days. For durability aspects, concretes and mortars were prepared to investigate the chloride and sulfate resistance respectively in accordance with appropriate ASTM standards. Rapid Chloride Penetration Test (RCPT) was conducted in accordance with ASTM C1202 to investigate the ability of concretes containing POFA to resist the penetration of chloride ions. Change in length and microstructure study for mortar bars containing POFA immersed in sodium sulfate were conducted to evaluate the effects of sulfate attack on POFA mortars. Concrete and mortar specimens were prepared using plain portland cement in order to use as control specimens. At age of 90 days, the results of compressive strength of all POFA concretes were higher than control concrete. All concretes containing POFA showed higher potential to resist chloride ions penetration compared to control concrete. All mortar bars containing POFA showed lower expansion and less porous structure than control mortar. Depending on the results of this investigation, it could be concluded that POFA could be successfully used as supplementary cementing materials to replace 20% of cement in concrete and mortar. © 2013 Korean Society of Civil Engineers and Springer-Verlag Berlin Heidelberg

Push tests on innovative shear connector for composite beam with cold-formed steel section

In this study, experimental tests were conducted to investigate the ductility and strength capacity of new shear connector. Push test specimens were prepared and tested according to EN1994-1-1 standard. The push test specimen consists of two cold-formed steel lipped channel sections oriented back-to-back to form an I-section beam, transverse metal deck and normal concrete slabs grade C25/30. Angle brackets were obtained from the same section of the beam and fastened to the web of steel beam to provide the shear connection. Two shear connectors were tested namely; “SC1” and “SC2” shear connectors. Both shear connectors showed a ductile behavior and had satisfied the ductility requirements of EN1994-1-1 standard. It was concluded that the ductile behavior of shear connectors could enhance the design of composite beam