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Articles 1 - 7 of 7
Full-Text Articles in Engineering
Enhancing Concrete Pavement Service Life Using Multiple Strategies To Reduce Cracking Potential, Dhanushika Mapa Mudiyanselage
Enhancing Concrete Pavement Service Life Using Multiple Strategies To Reduce Cracking Potential, Dhanushika Mapa Mudiyanselage
USF Tampa Graduate Theses and Dissertations
Over the past years, prevention of cracking in concrete structures, especially at early age, has been a challenge facing transportation agencies. During early age, restraint of thermal and moisture related volume changes causes cracking in concrete. This research focuses on evaluating the effectiveness of different cracking mitigation strategies that can be implemented, in different concrete elements, to reduce early-age cracking incidents and therefore enhance concrete service life. To this end, a battery of field and laboratory testing were conducted, and finite element analysis was performed to better understand the mechanisms of primary significance on minimizing cracking risks commonly associated with …
Influence Of Exposure Environments On The Durability Of Slag-Blended Cements, Joseph Onah Ukpata, P. A. M. Basheer, Leon Black
Influence Of Exposure Environments On The Durability Of Slag-Blended Cements, Joseph Onah Ukpata, P. A. M. Basheer, Leon Black
International Conference on Durability of Concrete Structures
Both chlorides and sulphates combine in seawater to affect the durability of reinforced concrete structures located in marine environments. This paper presents the results of an experimental study on slag blended cement systems, cured for 7 days, before exposure to a combined solution of sodium chloride (30 g/L) and sodium sulphate (3 g/L). Two slags of different chemical compositions, designated as slags 1 and 2 were respectively blended with Portland cement CEM I 52.5R at 30 and 70 wt.% replacement levels. Mechanical tests on mortar samples were complemented by microstructural examination and chemical characterisation on paste samples, all using a …
The Performance Of Concrete In A Marine Environment, Michael D. Thomas, Edward G. Moffatt
The Performance Of Concrete In A Marine Environment, Michael D. Thomas, Edward G. Moffatt
International Conference on Durability of Concrete Structures
This paper presents a summary of data from wide range of concretes following periods of marine exposure ranging up to 25 years. Data are presented from more than 100 different concrete mixtures. The various types of concrete include fibre-reinforced concrete (FRC), ultra-high performance concrete (UHPC), concrete with a range of supplementary cementing materials (SCM such as fly ash, slag, and silica fume) and replacement levels (e.g. up to 58% fly ash and 80% slag), lightweight-aggregate concrete (LWAC) and concrete containing alkali-silica reactive aggregate. Testing included measuring chloride concentration profiles, electrochemical corrosion measurements (for steel-reinforced concrete), and various electrical and mechanical …
The Synergistic Effect Of Nano-Silica With Slag On Frost Resistance Of Concrete, Yuan Lianwang, Zhou Zonghui, P Du, X Cheng, P Hou, L Zhang, Q Li
The Synergistic Effect Of Nano-Silica With Slag On Frost Resistance Of Concrete, Yuan Lianwang, Zhou Zonghui, P Du, X Cheng, P Hou, L Zhang, Q Li
International Conference on Durability of Concrete Structures
The frost resistance of concrete is one of the most important factors for its durability. Supplementary cementitious materials could effectively improve the frost resistance of concrete. On this basis, the synergistic effect of nano-silica (NS) with slag on the frost resistance of concrete is better than the single, which was investigated. Nano-silica and slag were employed as a partial substitute of cement. The effect of these on the related indexes, including the mass loss, relative dynamic elastic modulus and porosity of concrete were measured after specified number of freeze and thaw cycles. Results show that the frost resistance of nano-silica …
Effects Of Temperature And Curing Duration On The Stability Of Slag Cements In Combined Chloride-Sulphate Environments, Joseph Onah Ukpata, P. A. M. Basheer, Leon Black
Effects Of Temperature And Curing Duration On The Stability Of Slag Cements In Combined Chloride-Sulphate Environments, Joseph Onah Ukpata, P. A. M. Basheer, Leon Black
International Conference on Durability of Concrete Structures
This experimental study investigates the effects of temperature and curing duration on the stability of slag blended cement systems exposed at 20 °C and 38 °C to combined sodium chloride (30 g/L) – sodium sulphate (3 g/L) solutions. Two slags, designated as slag 1 and 2, having CaO/SiO2 ratios of 1.05 and 0.94, were respectively blended with Portland cement CEM I 52.5R at 30 wt.% replacement level. Mortar prisms and cubes with w/b ratio of 0.5 and binder/aggregate ratio of 1:3 were then prepared for length and mass changes. The samples were cured in lime water for either 7 …
Obtaining Homogeneous Silicon In The Process Of Alumothermic Reduction Of Silicon Dioxide, G. N. Chumikov, V. V. Klimenov, N. S. Tokmoldin, S. Zh. Tokmoldin
Obtaining Homogeneous Silicon In The Process Of Alumothermic Reduction Of Silicon Dioxide, G. N. Chumikov, V. V. Klimenov, N. S. Tokmoldin, S. Zh. Tokmoldin
Eurasian Journal of Physics and Functional Materials
The influence of charge components on emergence of a homogeneous phase of silicon in the process of silicon dioxide reduction by aluminium has been studied. Optimal process parameters affecting the quality of the end product have been identified. These include the ratio of components of the synthetic charge (CaO, SiO2 , CaF2 ), the optimal amount of SiO2 , the optimal amount of a reducing agent (Al) and the optimal Si/slag ratio. The homogeneous phase of silicon is easily separated from the slag, which contributes to the reduction of waste silicon during further technological operations.
Investigation Of Engineering Properties Of Normal And High Strength Fly Ash Based Geopolymer And Alkali-Activated Slag Concrete Compared To Ordinary Portland Cement Concrete, Nabeel Farhan, M Neaz Sheikh, Muhammad N. S Hadi
Investigation Of Engineering Properties Of Normal And High Strength Fly Ash Based Geopolymer And Alkali-Activated Slag Concrete Compared To Ordinary Portland Cement Concrete, Nabeel Farhan, M Neaz Sheikh, Muhammad N. S Hadi
Faculty of Engineering and Information Sciences - Papers: Part B
Fly ash-based geopolymer (FAGP) and alkali-activated slag (AAS) concrete are produced by mixing alkaline solutions with aluminosilicate materials. As the FAGP and AAS concrete are free of Portland cement, they have a low carbon footprint and consume low energy during the production process. This paper compares the engineering properties of normal strength and high strength FAGP and AAS concrete with OPC concrete. The engineering properties considered in this study included workability, dry density, ultrasonic pulse velocity (UPV), compressive strength, indirect tensile strength, flexural strength, direct tensile strength, and stress-strain behaviour in compression and direct tension. Microstructural observations using scanning electronic …