Creep of alkali-activated fly ash and slag concrete: Unveiling multiscale dynamics

Climate change is the main global concern today, triggering a transformative shift in several sectors, especially the construction industry. High carbon emissions during Portland cement (PC) production necessitate a gradual shift toward more environmentally friendly alternatives, such as alkali-activated materials (AAMs). AAMs offer a promising,...

Mitigating the autogenous shrinkage of ultra-high performance concrete by using rice husk ash

Concrete made with Portland cement has good behaviour under compressive stress, but it is weak in tension. Cracking caused by tension is a typical problem in concrete practice. High autogenous shrinkage at early ages is one of the causes of cracking, especially in high/ultra-high performance concrete. In that stage shrinkage is strongly related...

Carbonation of C-S-H gel and its Effects on the Carbonation Rate in Blended Cement Paste - An Experimental and Modelling Study

Supplementary cementitious materials (SCMs), like fly ash (FA) and blast furnace slag (BFS), are widely used in concrete to partially replace the cement clinker in the production of blended cement or directly replace part of Ordinary Portland cement (OPC) in the concrete. No matter how the SCMs are introduced, they can reduce the cost of...

Utilization of mswi bottom ash as a mineral resource for low-carbon construction materials: Quality-upgrade treatments, mix design method, and microstructure analysis

In recent years, considerable attention has been given to the utilization of municipal solid waste incineration (MSWI) bottom ash as a mineral resource for construction materials. MSWI bottom ash is the primary residue discharged after incinerating municipal solid waste. The generation of MSWI bottom ash is increasing dramatically with the wide...

Micromechanics-guided development of strain-hardening alkali-activated composites: Towards a low-carbon built environment

Alkali-activated Materials (AAMs), including those classified as geopolymer, are obtained through the reaction between a solid precursor and an alkaline solution. Compared with ordinary Portland cement (OPC) binders, these materials maintain comparable mechanical properties but have the advantage of reducing greenhouse gas emissions and...

Autogenous shrinkage of alkali-activated slag and fly ash materials: From mechanism to mitigating strategies

Alkali-activated materials (AAMs), as eco-friendly alternatives to Ordinary Portland cement (OPC), have attracted increasing attention of researchers in the past decades. Unlike cement, which requires calcination of limestone, AAMs can be made from industrial by-products, or even wastes, with the use of alkali-activator. The production of AAMs...

Experimental Study and Numerical Simulation of the Reaction Process and Microstructure Formation of Alkali-Activated Materials

Alkali-activated materials (AAMs) show promising potentials for use as building materials. Before the utilization, AAMs must satisfy the properties required from the construction sector, such as good durability and long-term service life. These properties mainly depend on the chemical and physical properties of the microstructure of AAMs. In the...

Carbonation mechanism of alkali-activated fly ash and slag materials: In view of long-term performance predictions

As the building sector is expanding, a growing interest in technologies that can reduce the CO2 emission from concrete production has led to partial replacement of cement with by-products from various industrial processes. Besides the partial replacement of cement, development of alkali activation technology ensures full replacement of cement in...

Non-saturated Chloride Diffusion in Sustainable Cementitious Materials

Chloride-induced reinforcement corrosion, caused by chloride diffusion in the unsaturated concrete cover, is a major durability problem of concrete structures. Current concepts for concrete mixture design and for service life prediction are generally based on the understanding of the chloride diffusion coefficient of saturated concrete. This...

Transport Processes in Hydrating Cementitious Coating Systems

Concrete is currently the most widely used material in construction field. A good performance of concrete structures is required for reaching the designed service life. However, the initial scatter in the quality of concrete is unavoidable in practice, possibly resulting from improper design, poor execution, or deterioration due to stresses...

Influence of interface and strain hardening cementitious composite (SHCC) properties on the performance of concrete repairs

In the construction industry the demand for repair and maintenance of concrete structures constantly increases. Still, the performance of current concrete repairs is not satisfactory and there is an urgent need for improvement. Understanding the damage development in a repair system, and how to predict, model and prevent its failure is critical...

Microstructure and Engineering Properties of Alkali Activated Fly Ash -as an environment friendly alternative to Portland cement

Alkali activated fly ash (AAFA), also named “geopolymer”, has emerged as a novel engineering material in the construction industry. This material is normally formed by the reaction between fly ash and aqueous hydroxide or alkali silicate solution. With proper mix design, AAFA can present comparable or superior engineering properties to Portland...

Microstructure and deterioration mechanisms of Portland cement paste at elevated temperature

Performance assessment of cement-based materials blended with micronized sand: Microstructure, durability and sustainability

Concrete is one of the most important construction materials in the world. However, Portland cement which is one of the constituents of concrete is responsible for about 5-10% of global CO2 emission. From sustainability point of view, therefore, it is important to search for materials which can be used to reduce or to replace Portland cement in...

Multiscale Lattice Boltzmann-Finite Element Modelling of Transport Properties in Cement-based Materials

Cement-based materials are the most widely used man-made materials in the world. The durability of cement-based materials has been a major concern due to the premature failure and serviceability issues of many reinforced concrete structures. Durability of cement-based materials is to a large content dependent on their resistance to the ingress...

Rice husk ash as a mineral admixture for Ultra High performance Concrete

Performance of Engineered Cementitious Composites for Concrete Repairs

Background and goals of this thesis The concrete repair, rehabilitation and retrofitting industry grows rapidly, driven by deterioration of, damage to and defects in concrete structures. However, it is well known that to achieve durable concrete repairs is very difficult. The failure of concrete repairs causes high economical, social and...