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...

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...

Effect of relaxation on eigenstresses and microcracking in concrete under imposed deformation

For the dimensioning of concrete structures it is customary to determine the forces and stresses occurring in construction elements on the basis of the prescribed loads. In an iterative process, the final dimensions of the elements and reinforcement are then determined. This process becomes less simple if not only the external loads, but also...

Autogenous shrinkage of early age cement paste and mortar

Concrete is a brittle composite material that easily fractures under tension. Due to the fact that the early-age deformation of the concrete member is restrained by adjoining structures, cracking can occur throughout the concrete prior to application of any load. The cracks would provide preferential access for aggressive agents penetrating in...

On local panel distortions due to hot-curing adhesives

For many joining applications, adhesive bonding is the favoured method. It provides the ability to join dissimilar materials such as metals and plastics. Adhesive bonds can be formed over large flange areas subsequently increasing the overall stiffness of the assembly. In some cases, however, the bonding process can lead to distortions, i.e....

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...

Autogenous Deformation and Internal Curing of Concrete

High-performance concrete (HPC) is generally characterized by a low water/binder ratio and by silica-fume addition, which guarantee a low porosity and a discontinuous capillary pore structure of the cement paste. Modern concretes possess some highly advantageous properties compared to traditional concrete, such as good workability in the fresh...