Evaluation of the Fresh Properties of Cement Pastes: Part I-Response Models Applied to Changes in the One-Variable-at-a-Time Method

The workability of cement-based materials is one of the features that makes these con struction materials the most used worldwide. Measuring and understanding how cement-based constituent materials affect fresh properties depends on the experimental plans. The experimental plans deal with the constituent materials used, the tests carried out, and the run of experiments. Here, the fresh properties (workability) of cement-based pastes are evaluated based on the diameter in the mini-slump test and the time in the Marsh funnel test being measured. This overall study is composed of two parts. In Part I, tests were carried out on several cement-based paste compositions incorporating distinct constituent materials. The effects of the distinct constituent materials on the workability were analyzed. Furthermore, this work deals with an approach to the run of experiments. A typical run of experiments was applied, with basic sets of mixed compositions being studied by only changing one input parameter at a time. This approach used in Part I is faced with a more scientific approach applied in Part II of the work where, based on the design of experiments, multiple input parameters were changed at a time. This work showed that a basic run of experiments is quick and easy to apply and leads to results for simple analyses; conversely, it lacks information for advanced analyses and scientific conclusions. The tests carried out included studies on the effect on the workability caused by changes in the limestone filler content, the type of cement, the water-to-cement ratio, distinct superplasticizers, and shrinkage-reducing admixture.info:eu-repo/semantics/publishedVersio

A bibliographic review of concrete obtained by alkaline activation and the specific case of the municipal solid waste incineration slag

The present bibliographic review work focuses on the approach and study of historical processes of slag resulting from the incineration of municipal solid waste, namely: An introduction to the history of Roman civilization and its building habits in the region of Pozzuoli, its engineering and architecture; Alkali-activated ligands, their Zeolitic compositions, geopolymers, chemical reactions and their crystalline phases, amorphous materials and the composition of aluminosilicates; Chemical and structural characterization of alkaline-activated materials and elements; Hybrid cements considered binders containing a percentage of OPC and another percentage of an aluminosilicate precursor and activated alcaline; Origin and treatment of municipal solid waste as well as incineration processes; Hybrid cements containing municipal solid waste incineration slag; An approach to the alkali activation of ligands with slag from municipal solid waste incineration. Finally, a conclusive top-down analysis of these issues.info:eu-repo/semantics/publishedVersio

Durability in alkaline-activated materials a review on the state of the art

The present work on durability in materials obtained by alkaline activation (AAM), in state-of-the-art review format, is structured as follows. (I) -The concept of alkali activated materials-composition-performance; (II) - The prediction of the useful life of AAM-methodologies and planning; (III) - The durability and properties of Engineering-mechanical tests-standards of specifications and tests (IV)-Degradation processes of Chemical Matrix-resistance to sulfates (SO4-²), acids (HCl), (H4²2SO4) (HNO3), (H3PO4), (HF), (H2CO3) and sea waters; (V) Degradation processes by mass transport - permeability, porosity, corrosion, carbonation, efflorescence and ice-thawed.info:eu-repo/semantics/publishedVersio

Durability of concrete with alkali-activated materials, a short literature review

The alkali-activated materials are being understood as the best chance to replace the Portland cement to become the concrete industry greener in terms of CO2 emissions. However, these alternatives binders face challenges, among others related to durability. The present work regards to a short literature review about the durability in concrete produced with binders that are alkali-activated materials.The mechanisms of degradation are discussed, namely due to acid attack, capillarity, carbonation, permeability , porosity and steel corrosion. Comparison to the concrete permeability, porosity and steel corrosion. Comparison to the concrete that used Portland cement as binder is frequently used.info:eu-repo/semantics/publishedVersio