Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 75 for “"Concrete mixes"”.
-
Optimizing the usage of fly ash in concrete mixes
… ash (FA), on a larger scale in the cement and concrete industry, by utilizing the FA to the optimum. In this study concrete mixes of 25 MPa, 35 MPa and 50 MPa with FA partially substituting the cement at 30%, 40%, 50% and 60% were produced and numerous tests were performed to determine the …
-
Evaluation of ultrasound method for determining aggregate gradations in asphaltic concrete mixes
… aggregate gradation differences in asphaltic concrete pavements. Empirical data had previously been used to suggest that the more coarse the gradation, the less incidence's of rutting. It is my thesis that the more coarse the gradation, the higher the velocity of a sound wave through the …
-
Evaluation of rutting resistance of coarse graded aggregate asphaltic concrete mixes in Clark County, Nevada
… of utilizing coarse aggregates in asphaltic concrete pavements for reducing rutting in Clark County, Nevada. Previous specifications used for asphaltic concrete mix designs in the Clark County area allowed for a wide range of aggregate gradations. The aggregate gradations in the asphaltic …
-
The viability of using gold mine tailings as a substitute for fine aggregate in concrete mixes
… region as a substitute for fine aggregates in concrete. Laboratory experiments were used to determine the physical properties, such as density and particle size distribution (PSD) and compare these physical properties with the other conventional fine aggregates used in this research, as well as …
-
Durability Assessment and Service Life Prediction of Concrete in Extreme Aggressive Environment
… elements by assessing the performance of various concrete mixes for chloride resistance. The study focuses on establishing and developing correlations between chloride diffusion rates and concrete resistivity. By identifying these correlations and based on the target service life, the research …
-
Effect of curing procedure on the freezing and thawing durability of concrete
Results indicate that the durability of the concrete mixes using poor aggregates can be improved to a considerable extent by moist-curing.
-
Service life extension of reinforced concrete structures using hydrophobic impregnation
… increasing premature deterioration of reinforced concrete structures, mainly due to rebar corrosion, has become a worldwide concern. This has been attributed to insufficient quality and quantity of cover concrete resulting from inadequate mix design and poor onsite workmanship respectively. …
-
Time-dependent losses in post-tensioned prestressed concrete
… and deflections of Class 1 uncracked prestressed concrete beams. The main influencing factors considered were environmental conditions, loading conditions,size and shape of members and concrete mix composition. Twenty seven beams consisting of both I- and rectangular sections with different …
-
Biogenic acid corrosion of sewer concretes with different binders: in-situ and model studies, with advancement of the life factor prediction method
… Acid Corrosion (BAC) is the biodeterioration of concrete caused by biological and chemical activities of bacteria that grow in an acidic environment. Such environments are typical in sewer systems, which collect wastewater from households, industries, and urban and storm water runoff, and convey …
-
High Strength Pervious Concrete
Pervious concrete is increasingly being utilised in the construction of driveways, parking lots, and pavement in many industrialised nations. Testing must be done to assess the performance of this new kind of high-performance concrete in order to establish material specifications for pervious …
-
The Development of the Strength Index Method and Protocol for Assessing the Use of Solid Waste Materials in Concrete
… as reactive using the 28 day index values. Concrete containing sludge ash generally exhibited less compressive strength and modulus of elasticity when compared to concrete containing 100% portland cement (control) at all test ages. The stress-strain relationship for the BP and CR concretes …
-
Development of low-clinker concrete: partial replacement of cement with calcined clay and limestone, based on selected African raw materials
… the kaolinite content of the clay. Further, LC3 mixes with clinker content in the range of 40% to 70% were designed using the mixture design 3-factors approach. The compressive strength of mortar with a water/binder ratio of 0.4 was used as the performance parameter for optimising proportions. …
-
Rapid assessment of the potential chloride resistance of structural concrete
… study benchmarked the chloride resistance of concretes mixes at the limit state of BS 8500-1:2006 using the newly published CEN TS12390-11. Of the three allowed methodologies, the immersion test was carried out. At least two water-cement ratios were produced for each mix design to enable …
-
The use of construction and demolition waste in concrete in Cape Town
Incorporating recycled aggregates in concrete, despite the fact that effective technologies are available, is being adopted at a slow rate. These shortcomings have been associated with poor quality recycled aggregate (RA) products, lack of guidelines facilitating the use of RAs in various …
-
Using Maturity to Predict Girder Camber
… determine if differential camber of prestressed concrete girders could be reduced by accurate prediction of initial camber at release of prestress. Maturity at prestress transfer was used to calculate modulus of elasticity for predicting camber at release. The research consists of a literature …
-
Performance Enhancement of Concrete Produced with Treated Demolition Waste Aggregates
… and the high uncertainty of recycled aggregate concrete structural performance have limited its utilisation in structural applications. The current literature showed only a few studies on the use of treated recycled aggregate from construction and demolition waste and its effect on the different …
-
Transfer Length, Development Length, Flexural Strength, and Prestress Loss Evaluation in Pretensioned Self-Consolidating Concrete Members
… determine the effect of using self-consolidating concrete versus normal concrete on transfer and development lengths, and flexural strengths of prestressed members. Three small rectangular members were made, two cast with SCC mixes and one cast with a conventional mix, to determine the transfer …
-
Engineering properties and structural behaviour of high strength reinforced concrete beams
High Strength Concrete (HSC) has become a viable alternative to lower strength concrete. However, its utilisation is increasing faster than the development of suitable design recommendations. This is because limited and diverse investigations have been carried out concerning engineering properties …
-
Alkali-Aggregate reaction in Western Cape concrete
… in aggregates and alkali in the pore solution of concrete. Through research, the reaction has been categorised into three main classes depending on the type of aggregate used. Alkali-silica reaction, ASR, being one of those classes, is the most common one and is the primary concern in the local …
-
The influence of crystalline admixtures on the mechanical and durability properties of cracked and uncracked concrete
… over their service lives. Self-healing of concrete promotes reduced water permeability without the need for maintenance and repair. Innovative concrete selfhealing methods include the use of microencapsulation, hollow glass tubes, bacteria, and crystalline admixtures. Crystalline admixtures …
Page 1 of 4