With the development of new and efficient admixtures for concrete, the production of high strength concrete (HSC) is becoming available at competitive prices. The behavior and properties of HSC are being studied around the world, but one of the advantages of concrete, namely that it can be cast using local materials, when dealing with new concretes can be a disadvantage, because research conducted elsewhere does not necessarily apply to the materials available near the construction site. The HSC studied in this research was cast using commercially available materials that require no special investments to procure. Samples were cast according to current standard provisions and tested at different ages in order to determine the mechanical properties of the produced concrete that are of interest to structural engineers and construction professionals. The samples were cured in different conditions in order to study the influence this has on the properties of the concrete. Results obtained show that some properties of high strength concrete are influenced by curing conditions, these properties are highlighted in the paper

This paper investigates nine PVA fiber-reinforced cementitious composites with varying fiber content (1–2.5%) and types (oil-coated and non-coated). The experimental compositions utilize locally available cement, high volumes of fly ash, silica fume, PVA fibers, and a superplasticizer, entirely omitting natural aggregates. Key parameters evaluated include bulk density, compressive strength, secant modulus of elasticity, flexural tensile strength, fracture energy, and structural design applicability. The results show that FRCs without natural aggregates achieves significantly lower densities (1500–1720 kg/m³). Compressive strength is influenced by matrix density, with the highest value recorded at 30.98 MPa. The high fly ash content reduces the secant modulus of elasticity, while flexural tensile strength follows a similar pattern to compressive strength. Oil-coated fibers generally lower fracture energy, except for the 1.5% PVA content, where the 2.5% composition performs best. All specimens exhibit tension softening rather than the strain-hardening behavior of ECCs. Structural design equations were developed, though experimental validation is necessary. The 2.5% PVA composition increases the compression zone height by 7% while requiring 2% more reinforcement. As a sustainable alternative to conventional concrete, the composites offer promising mechanical properties and structural viability for construction applications.

In structural engineering, strain and displacement are critical parameters, and measuring these parameters outside of the laboratory is a challenge for concrete researchers. Recent advances have enabled digital image correlation (DIC) to calculate the concrete surface displacements of chosen targets in a series of images recorded during an experiment. This paper presents a comparison between traditional and optical measurements to evaluate the efficiency of the DIC technique in recording the deformations of reinforced concrete beams. Tests were perfomed on two small-scale reinforced self-compacting concrete beams with small circular openings in 3-point bending.

This study examines the use of electronic waste (e-waste) as an alternative material in concrete for sustainability and natural resource conservation. Various e-wastes, such as Polyvinyl Chloride (PVC), Glass-Reinforced Plastic (GRP), Glass Fiber-Reinforced Polymer (GFRP), cross-linked polyethylene (XLPE), polyethylene (PE), electronic cable waste (ECW), Waste Electrical Cable Rubber (WECR), copper fiber (Cu Fib.), aluminum Fibers (Al fib.), steel fibers, basalt fibers, glass fibers, aramid−carbon fibers, Kevlar fibers, jute fibers, and optical fibers, were tested for influence on compressive, flexural, tensile strength, modulus of elasticity, and water absorption. Outcomes show that fine particle waste at low levels (0.2–1.5%) can improve mechanical performance, while higher levels of replacement or coarse particles generally reduce performance. Mechanical and physical properties are highly sensitive to material type, particle size, and dose. Life cycle assessment (LCA) and predictive modeling are recommended as validation for sustainability benefits.

This paper presents a combined theoretical and experimental investigation of an innovative building material known as PVA Fiber Reinforced Composite - an advanced class of cement-based materials renowned for their exceptional flexibility and superior crack control, overcoming the limitations of traditional concrete. The study aimed to develop new compositions and conduct a comparative performance analysis. The proposed composites utilize locally available cement at conventional dosage levels, incorporating high volumes of fly ash, silica fume, PVA fibers, and a superplasticizer, while entirely omitting stone and sand aggregates. A total of nine compositions were designed and tested: four with uncoated PVA fibers at 1%, 1.5%, 2%, and 2.5%, four with oil-coated PVA fibers in the same proportions, one control mix containing sand aggregates. The research evaluated key experimental and design parameters, including bulk density, compressive strength and strain, secant modulus of elasticity, flexural tensile strength and deflection, fracture energy, and structural design applicability. As a novel building material aimed at enhancing both environmental sustainability and structural performance, the studied fiber-reinforced composites exhibit promising characteristics, positioning them as viable alternatives for practical construction applications.

Corrosion of the reinforcement is a constant vulnerability for reinforced concrete structures exposed to aggressive environments. High strength concrete is known to prevent corrosion of the reinforcement, in a non-cracked state, when exposed to aggressive environments. The purpose of this study is to assess the opportunity of using high strength concrete in cracked elements exposed to corrosion and compare them with non-exposed elements. A series of simply supported reinforced high strength concrete beams with concrete cover of 25 and 50 mm were pre-cracked, up to a service life crack of 0.1 mm, further exposed to accelerated corrosion through a process of electrolysis and finally tested to failure. A series of non-exposed witness specimens were also tested to failure. All elements were designed with the same bending capacity. The flexure behaviour was assessed by plotting experimental and theoretical ultimate limit state position of the neutral axis at midspan and the results show no significant differences in the overall behaviour, despite the affected reinforcement, between the corroded and non-corroded elements. Moreover, the design bending moments were approximately 40% lower than the experimental ones, even for corroded beams, which can be a significant strength reserve of the beams, useful in aggressive environments.