A Review of the Mechanical Properties and Durability of Ecological Concretes in a Cold Climate in Comparison to Standard Ordinary Portland Cement-Based Concrete

Abstract

Most of the currently used concretes are based on ordinary Portland cement (OPC) which results in a high carbon dioxide footprint and thus has a negative environmental impact. Replacing OPCs, partially or fully by ecological binders, i.e., supplementary cementitious materials (SCMs) or alternative binders, aims to decrease the carbon dioxide footprint. Both solutions introduced a number of technological problems, including their performance, when exposed to low, subfreezing temperatures during casting operations and the hardening stage. This review indicates that the present knowledge enables the production of OPC-based concretes at temperatures as low as −10 °C, without the need of any additional measures such as, e.g., heating. Conversely, composite cements containing SCMs or alkali-activated binders (AACs) showed mixed performances, ranging from inferior to superior in comparison with OPC. Most concretes based on composite cements require pre/post heat curing or only a short exposure to sub-zero temperatures. At the same time, certain alkali-activated systems performed very well even at −20 °C without the need for additional curing. Chemical admixtures developed for OPC do not always perform well in other binder systems. This review showed that there is only a limited knowledge on how chemical admixtures work in ecological concretes at low temperatures and how to accelerate the hydration rate of composite cements containing high amounts of SCMs or AACs, when these are cured at subfreezing temperatures.

Increasing the Corrosion Resistance and Durability of Geopolymer Concrete Structures of Agricultural Buildings Operating in Specific Conditions of Aggressive Environments of Livestock Buildings

“…At the same time, concrete of increased resistance, as a rule, has good resistance to aggressive environments, regardless of the type and origin of the aggressive environment. Therefore, it seems expedient to increase the inherent resistance of concrete structures, using the variability and adaptability of its structure to environmental conditions, ensuring the durability of structures at several levels [34][35][36][37].…”

Frost Resistance of Alkali-Activated Concrete—An Important Pillar of Their Sustainability

“…The ratios 80/90 and 90/10 were found to be very poor from the point of view of very quick setting; see for example Reference [28]. Mortars with total dry mass of the activator ∑ = 10% and 15% were prepared for R/S = 34/66 and R/S = 60/40, and mortars with ∑ = 10% and 17.6% were also prepared for R/S = 100/0; see Table 2.…”

“…AAMs are also considered very durable [21][22][23][24][25][26][27][28], which is another very important pillar of sustainability, but there are also some problems, which are collected, for example, in [27]. Among the most important are, inter alia, rapid setting and poor processability, high shrinkage, complicated and not fully understood chemistry, and limited large-scale use.…”

Review article: Atmospheric Pressure, Water with Air, Porosity and Strength of Concrete (In memory of Professor László A Gömze)

“…Since then and until today, the majority of researchers believe that the strength of concrete depends most on the strength of the hardened binding material (as a hardened adhesive) [3][4][5]. In particular, the quality of the binding materials used is considered to be the main condition for a high-quality chemical reaction that occurs between them and water during the hardening of the binder materials and which underlies the production of concrete [6][7][8][9][10][11]. This reaction is called cement hydration of cement.…”