Microstructure and properties of hybrid coal gangue-based alkali-activated cement

Addition of Portland cement in low-calcium aluminosilicate-based alkali-activated materials can provide rapid hardening at room temperature, thus modifying microstructure and mechanical properties. In the present study, the effect of Portland cement addition on alkali-activated materials, cured at room temperature, was analysed by mechanical...

Drying shrinkage of alkali-activated slag concrete with natural/recycled aggregates

Each year a large amount of construction and demolition waste (CDW) is generated in the European Union. For sustainability development the CDW is recycled and re-used. To promote the use of CDW, recycled aggregates from CDW were incorporated in alkali-activated concrete (AAC), which mainly consisted of secondary materials or industrial by...

Effect of ultra-fine fly ash on the mechanical and shrinkage properties of ultra-high performance concrete

This paper reports on a study to determine the possibility of using ultra-fine fly ash (UFA) for partial or total replacement of normal fly ash (NFA) in ultra-high performance concrete (UHPC). Workability, microstructure, porosity, drying shrinkage as well as mechanical properties were comprehensively studied to investigate the influence of UFA...

Development of an ecological high strength and high ductility cementitious composites (eco-hshdcc) incorporating glass powder

Most of the waste glass, such as flat glass, glass bottle, is buried in the landfill, which is not desirable because it is not biodegradable and is not conducive to the long-term development of the environment. The glass powder (GP) with a certain fineness has excellent pozzolanic effect and can be used as a potential supplementary cementing...

Application of ultra-fine fly ash as cement replacement for sustainable concrete with optimal packing design

In the present study, a proprietary 0.2 tonne/h Dusty Cloud Separation (DCS) technology prototype by Value Ash Technologies NV (Belgium) was used to obtain ultra-fine fly ash as a novel by-product. Two types of Class F fly ash were used: separated fly ash (FA1) with particle size < 9.3 μm and ultra-fine fly ash (FA2) < 4.6 μm as sub-fraction of...

Compressive strength and chloride ion permeation resistance of mortar containing clinker with different mineral composition as an aggregate

The purpose of this study is to clarify the performance of cement hardenings containing clinkers which are utilized as aggregate by evaluating the compressive strength and chloride ion penetration resistance of the mortars. Here, the fine aggregate used in this study were the ordinary Portland cement clinker and the clinker with more waste as an...

Properties of concrete blocks made with recycled concrete aggregates: From block wastes to new blocks

Large amounts of construction and demolition wastes (C&DW) especially concrete wastes are generated annually and will increase in the future. Until now, only a small fraction of concrete wastes is re-used as recycled concrete aggregates (RCA) in the manufacture of concrete. In this paper, the feasibility of using RCA obtained from old concrete...

Influence of the saturation state of recycled sand on mortars compressive strength

This paper investigates the water content of pre-saturated recycled concrete aggregates (RCA) that has a diameter of 1-4 mm called recycled sand (RS), in order to determine the degree of saturation of the RS. It also puts forward the effects of the saturation state of the RS on the mechanical properties. For this matter, experiments were...

Potential of soil bacteria from the comarca lagunera, north-east Mexico for bioconcrete development

Sustainability or environment friendly green technology is based on the use of agents of biological origin that can mimic nature in their process applications. The production and use of conventional Portland cement is significant contributor to emission of greenhouse gases and the resultant global warming. Microbial induced carbonate...