scispace - formally typeset
Search or ask a question
Author

H Beushausen

Bio: H Beushausen is an academic researcher. The author has contributed to research in topics: Concrete cover. The author has an hindex of 1, co-authored 1 publications receiving 23 citations.

Papers
More filters
Journal Article
TL;DR: In this article, a group of researchers from different parts of the world carried out comparative tests on the quality of concrete cover, applying the most commonly accepted international test methods, which indicated that the South African oxygen permeability and chloride conductivity test methods are successful in characterising concrete cover in respect of important deterioration mechanisms.
Abstract: Over the last decade, an approach to improving the durability of reinforced concrete construction has been developed in South Africa. The durability index test methods applied in this approach are unique to the country. Internationally, similar trends can be observed and a number of test methods for the quality assessment of hardened concrete, particular the cover zone have been developed world-wide. A group of researchers from different parts of the world carried out comparative tests on the quality of concrete cover, applying the most commonly accepted international test methods. The results indicate that the South African oxygen permeability and chloride conductivity test methods are successful in characterising the concrete cover in respect of important deterioration mechanisms. A good correlation exists between results obtained from these index test methods and those obtained from related test procedures applied overseas.

24 citations


Cited by
More filters
Journal ArticleDOI
TL;DR: In this article, three ground granulated slags (FeMn arc-furnace (GGAS), Corex (GGCS), and blastfurnaces (GGBS) slags from different sources were used to make concretes using two w/b ratios (0.40 and 0.60) and three slag replacement levels (20, 35% and 50%).
Abstract: Three ground granulated slags (FeMn arc-furnace (GGAS), Corex (GGCS) and blastfurnace (GGBS) slags) of varying chemical composition, and from different sources were used to make concretes using two w/b ratios (0.40 and 0.60) and three slag replacement levels (20%, 35% and 50%). The effect of chemical composition and replacement level of slags on the chloride penetration resistance of the concretes was assessed using the chloride conductivity test. The results showed that the chloride penetration resistance of concrete increases with decreasing w/b ratio and increasing slag replacement level. In the GGAS concretes, despite having relatively low SiO2 and high MgO content, its significantly high Mn2O3 and low Al2O3 content was found to have a negative effect on the chloride penetration resistance of the concrete. The significantly high chloride penetration resistance of GGCS concretes was partly attributed to both its high CaO content and particle fineness. Only GGCS concretes showed a trend of increasing chloride penetration resistance with increased particle fineness; GGBS and GGAS concretes did not show any trend between particle fineness and chloride penetration resistance. The slag activity index was found to be a better indicator of chloride penetration resistance in concrete than the slag hydraulic index.

68 citations

Journal ArticleDOI
TL;DR: In this paper, the authors present a revised model for concrete carbonation, which expands common carbonation models by accounting for the effect of relative humidity on both diffusion and chemical reactions.

63 citations

Journal ArticleDOI
TL;DR: In this article, the authors examined some properties of concrete, such as strength, oxygen permeability and sorptivity using starch [cassava (CA) and maize (MS)] as admixtures.
Abstract: This paper examines some properties of concrete, such as strength, oxygen permeability and sorptivity using starch [cassava (CA) and maize (MS)] as admixtures. Concrete cubes containing different percentages of the CA and MS by weight of cement (0, 0.5, 1.0, 1.5 and 2.0 %) were cast. Compressive strength tests were carried out after 3, 7, 14, 21, 28, 56, 90, 180, 270 and 365 days of curing. Oxygen permeability and sorptivity tests were carried out on another set of concrete specimens with the same percentages of starch at 7, 28, 90, 180, 270 and 365 days. Oxygen permeability and sorptivity tests data obtained were subjected to Kruskal–Wallis one-way analysis of variance by ranks. The strength increase after 1 year over the control for CA 0.5 and CA 1.0 are 2.7 and 3.8 % respectively, while MS 0.5 and MS 1.0 gave 1.5 % increase over control. These results showed a decrease in oxygen permeability and rates of sorptivity, with concretes containing starch as admixtures giving better performance than the control concretes.

33 citations

Journal ArticleDOI
TL;DR: In this paper, the authors evaluate the practicality of Durability Index (DI) performance-based specifications that have been implemented on a large scale in a major infrastructure project involving bridge and other structures in Gauteng Province, South Africa.

31 citations

Journal ArticleDOI
TL;DR: In this article, short and long-term properties of alkali-activated fly ash concrete, namely, compressive, flexural and splitting tensile strengths, modulus of elasticity, Poisson ratio, early-age and drying shrinkage, creep and durability performance have been investigated.
Abstract: Short- and long-term properties of alkali-activated fly ash concrete, namely, compressive, flexural and splitting tensile strengths, modulus of elasticity, Poisson ratio, early-age and drying shrinkage, creep and durability performance have been investigated in this paper. Blended ordinary Portland cement–fly ash concrete was used as a reference. The average compressive and flexural strengths of alkali-activated fly ash concrete at 28 d were 45 MPa and 5·8 MPa, respectively; drying shrinkage and creep values were about 360 and 200 microstrain, respectively, at 1 year. The total early-age shrinkage during the first 24 h of curing was lower for alkali-activated fly ash concrete at 1460 microstrain compared to 2800 microstrain for blended cement concrete. The use of this non-Portland cement containing material for producing precast concrete units can utilise high volumes of fly ash and potentially reduce the carbon footprint of the final product.

24 citations