Tanvir Ahmed

University of Western Australia | UWA · Faculty of Engineering, Computing and Mathematics

Cementitious mix with very-low-tricalcium aluminate (C3A) cement or VLAC (C3A ≤ 3%) as the primary binder requires lower water to binder ratio to attain a target flowability than that with moderate-C3A cement or MAC (6% < C3A ≤ 10%). Hence, better mechanical performance, as well as good flowability, can be achieved for the mix with VLAC. Utilizing...

Ultra-high performance concrete (UHPC), owing to containing very high cement content, usually exhibits high shrinkage compared to normal strength concrete (NSC). Shrinkage may lead to the formation of cracks. Excessive shrinkage cracks may impair the mechanical performance of concrete and its durability. In this study, the influence of high-volume...

To ensure ultra-high performance, in terms strength and durability, coarse aggregate is typically avoided in UHPC (ultra-high performance concrete). Instead, very fine quartz sand is usually used as the only aggregate. However, excessive extraction of sand from natural resources and its grinding and refining processes to prepare very fine quartz-ri...

Substituting cement by supplementary cementitious material (SCM) is the most-practiced approach of reducing CO2 footprint of concrete. However, in case of UHPC, for which ultra-high performance in terms of both strength and durability is of utmost importance, high-volume reduction of cement is often difficult or highly challenging. In this study, t...

Ultra-high-performance concrete (UHPC), despite its superior mechanical and durability properties, has a high CO2 footprint owing to its high portland cement content. This drawback can be offset to a notable extent if a high volume of supplementary cementitious materials can be utilized to produce UHPC while maintaining mechanical and durability pr...

An extended study was carried out to explore the possibility of recycling of concrete made with brick aggregate as coarse aggregate. Demolished concrete blocks were collected from six demolished building sites and then crushed into coarse aggregate manually. Physical properties of the coarse aggregate collected from the blocks were evaluated. Cylin...

Traditionally, critical path method (CPM) is widely used with manual resource assignment for planning and scheduling of the construction projects. This is predominant in the construction industry of Bangladesh. Therefore, the industry often faces challenges to complete construction projects in minimum possible time with optimum use of resources. Al...

Effects of different chemical admixtures on fresh and hardened properties of prolonged mixed concrete and their cost-effectiveness were investigated. Influence of sand to aggregate volume ratio, cement content, and use of chilled mixing water on the properties of prolonged mixed concrete was studied as well. Different concrete mixtures were prepare...

An experimental investigation was carried out to study the effects of types of chemical admixture on fresh and hardened properties of ready mix concrete. For conducting the investigation different concrete mixtures were prepared using six different types of chemical admixture (one water reducer based on lignosulfonate; and five superplasticizers ba...

The global high growth rate of population and economic development has led to an increased volume of concrete consumption each year. Roughly around 18 billion metric tons of concrete is consumed globally each year. Consumption of such a huge volume of construction materials for making new infrastructures may create a sustainability crisis in the ne...