A new mixture proportioning method is developed for performance-based concrete with supplementary cementitious materials (SCMs). The method is based on the thermodynamic calculations of the properties for concrete and identifying the mixtures that satisfy a predefined set of performance criteria. This new approach considers the chemical composition and reactivity of SCMs while proportioning concrete mixtures. Performance criteria examples are shown for a bridge deck (corrosion and freezing-and-thawing damage), an unreinforced pavement (salt damage), and a foundation (moderate sulfate and alkali-aggregate reaction). The method is used to proportion concrete mixtures satisfying these three performance criteria using four ashes per mixture. Experiments show that these mixtures met the targets. The proposed approach can proportion mixtures that are optimized for predefined performance using a wide range of SCMs, which can be useful in reducing the cost and carbon footprint of concrete.

This paper investigates the structural performance of large-scale lightweight self-consolidating concrete (LWSCC) and lightweight vibrated concrete (LWVC) beams made with expanded slate coarse aggregates (ESCAs) and expanded slate fine aggregates (ESFAs) under flexural loads. Nine large-scale concrete beams were cast with different types of lightweight aggregate (either ESCA or ESFA), coarse-to-fine aggregate ratios (0.5 to 1.5), and total binder contents (550 and 600 kg/m3 [34.3 and 37.5 lb/ft3]). The structural performance of the tested beams was assessed based on the characteristics of the load-deflection response, cracking pattern, displacement ductility, energy absorption, cracking moment, and ultimate flexural strength. The reliability of code-based expressions in predicting the cracking and ultimate moment capacity of the tested beams was also investigated in this study. The results indicated that using ESFA better improved the beam’s cracking moment capacity, deformability, ductility, and energy absorption capacity compared to using ESCA. Although LWSCC exhibited a lower modulus of elasticity than normal-weight SCC, the deflection values observed in the LWSCC beams under service loads were well within the allowable limit provided by BS 8110. The measured crack widths at the service loads for all tested beams ranged from 0.20 to 0.26 mm (0.008 to 0.01 in.), satisfying the limits proposed by ACI 318, CSA A23.3, and BS 8110 design codes for durability aspects.

Herein, the first trial to investigate the possibility of using one type of sugar beet waste, named carbonation lime residue after calcination (CCR), as an additive for alkali-activated slag (AAS) cement was explored. For this reason, typical AAS cement was prepared, then slag was partially replaced with CCR at levels ranging from 2.5 to 15% by weight. To explore the effect of CCR on the properties of AAS pastes, typical traditional tests such as flowability, setting time, and compressive strength at various ages were measured. In addition, different types of durability such as accelerated aging, water-air cycles, water-hot air cycles, HCl attack, and cyclic wetting in 5% Na2SO4 and drying at 80°C (176°F) were explored. The results were analyzed with different advanced devices. The results showed that it is possible to use CCR as an additive, similar to CaO, for AAS cement. The flowability and setting time decreased with the inclusion of CCR. The inclusion of 5% CCR in AAS cement was the optimal content, which proved the best compressive strength, microstructure, and durability. On the contrary, the inclusion of 15% CCR showed a negative effect. The pronounced outcomes of this investigation may be the solution for sugar beet waste landfills and improving the properties of AAS cement.

The American Concrete Institute (ACI) provides guides, specifications, and code documents related to concrete durability. The authors reviewed two code documents from ACI Committees 318 and 350, two guidance documents from ACI Committees 201 and 222, and a specification document from ACI Committee 350, and observed that several discrepancies exist in terms of providing uniform durability requirements for freezing and thawing and chemical sulfate attack of concrete, and allowable chloride limits for new construction. By analyzing existing concrete durability data from published literature, laboratory testing, and field exposure sites, recommendations on unified durability requirements and exposure class descriptions are made for potential adoption by ACI Committees 201, 222, 318, and 350.

The mechanical potential, the durability, and the most varied uses of structures have been studied and disclosed. However, there is still a gap regarding the determination of mixing ratios using a simple, accessible mixture design method that allows the determination of the ideal ratio of mixture constituents. Some studies on ultra-high-performance concrete (UHPC) mixtures did not present a method to define the mixing ratio with different materials and fiber contents, with high mechanical strength and no workability loss. To develop a method of mixing design from informational parameters of the materials, this paper presents a method of dosing UHPC. The proposed method is based on the packaging of particles through the previous evaluation of the percentages of each material according to its particle size distribution. Results showed that the proposed mixture design method can grant high potential compressive strength to the mixture. There was also a linear relation between higher matrix compacity and compressive strength. The composition with higher compacity—that is, the lowest void ratio of the mixture—presented an increase of 20% in compressive strength compared to the mixture with less compacity.