We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
A rational framework for evaluation and mix design of fly ash, with extension to supplementary powders, using SAI, k-factor, and effective-water correction
AI summary Read the abstract
This study tested fly ash, bottom ash, marble powder and other powders used in concrete, examining how a common strength test can give misleading results. It proposes a revised method using an "efficiency factor" and water-content corrections to better judge how much these materials actually contribute to concrete strength.
The evaluation of fly ash and supplementary powders in concrete is commonly based on the strength activity index (SAI) determined under standardized procedures. However, differences in replacement level, water control, and workability criteria influence the effective water–cement ratio and consequently the measured SAI. This study critically examines codal provisions and experimentally evaluates fly ash, ground fly ash, ground bottom ash, marble powder, and bio-fly ash, representing different levels of fineness and reactivity. The results demonstrate that SAI does not consistently represent the intrinsic contribution of a material because it reflects the combined effects of cement hydration, dilution, particle packing, and pozzolanic reaction. Consequently, materials with negligible reactivity may still exhibit positive SAI values due to the contribution of the remaining cement. Strength contribution is therefore examined through an efficiency factor ( k -factor) within an effective water–cement ratio framework. The framework is extended to concrete mix design using the equivalent cementitious content (c+ k f), enabling powders to be proportioned according to their strength contribution. A water-correction procedure accounting for sand absorption, powder moisture, and water contributed by liquid plasticizer is also proposed. Because conventional identification of the saturated surface-dry condition is unsuitable for very fine powders, an indirect performance-based approach is adopted. The resulting framework integrates material verification, SAI interpretation, effective-water correction, and k -factor-based mix design.
More Papers Like This
Factors Affecting the Performance of Fly Ash–Slag Geopolymers
AI summary Read the abstract
Researchers review recent advances in blast furnace slag and fly ash alkali-activated materials, identifying gaps in how amorphous phase composition, particle size of solid activators, and shrinkage behavior are accounted for in mix design, and calling for more systematic multiobjective optimization to advance one-part geopolymer cements toward industrial adoption.
Research Trends on the Utilization of Industrial and Domestic Waste for Sustainable Pavement Materials
AI summary Read the abstract
Researchers reviewed 15 studies on industrial and domestic waste — fly ash, slag, plastic waste, and recycled concrete — as pavement materials, finding that fly ash is the most studied additive and that proper waste incorporation generally improves Marshall Stability and compressive strength while reducing dependence on virgin natural aggregates.
Comparative evaluation of cement stabilized well graded sand using rice husk ash, fly ash, and recycled plastic fibers for subgrade applications
AI summary Read the abstract
This study is about road construction, not human health directly, researchers found that mixing a small amount of cement with fly ash (a waste product from burning coal) creates stronger, more stable road foundations while cutting cement use in half. This matters because cement production is a major source of pollution, so using waste materials like fly ash instead could mean cleaner air and less environmental damage from building roads. Note: the recycled plastic fiber option tested here didn't perform well structurally, and the study didn't examine microplastic shedding or health effects from any of these materials.
Experimental Investigation on the Mechanical Properties of Concrete with Partial Replacement of Fine Aggregate by Plastic Waste
AI summary Read the abstract
Researchers partially replaced fine aggregate in concrete mixtures with processed PET and other waste plastic particles and found an optimal replacement level that preserved acceptable compressive and tensile strength while reducing density, beyond which plastic-to-cement bonding degraded mechanical performance, suggesting a viable route for incorporating plastic waste into lightweight non-structural construction.
Investigating the Viability of Recycling Rice Husk Ash and Plastic Bag Waste to Enhance Durability of Lightweight Concrete
AI summary Read the abstract
Researchers investigated using recycled rice husk ash and plastic bag waste to enhance durability of lightweight concrete, finding that these waste materials improved certain mechanical and durability properties while reducing environmental impact of construction.
Research digests by email
When a large batch of papers lands in the Atlas, we read through it and send a short write-up of what stood out.