Effect of Elevated Temperatures on the Mechanical and Durability Properties of Green Concrete with Waste Glass Powder

Abstract. Problem. Decorative concretes in products of complex geometric shape react to all the combined influence of environmental factors. The synergistic action of internal and external factors leads to a significant deterioration in the structural and mechanical and aesthetic properties of the material of architectural products. It is known that the microstructure of concrete makes a significant contribution to the formation of the integral structure of products. There is a need to improve the properties of the microstructure of concrete in order to ensure durability and operational reliability of the material of decorative elements. In particular, there is a need to obtain reliable structural connections at the interface between discrete components of the composite. The paper presents results of studies of damage to cement stone. Damage is physically interpreted as presence of various microdefects (cracks, pores, etc.) scattered in a volume of the composite in the mechanical aspect. Goal. The purpose of the study is to improve the properties of decorative concrete by directionally changing the initial damage to the microstructure by the targeted use of organo-mineral additives and discrete fibers of certain geometry. Methodology. Studies of the properties of 25 compositions of cement stone were carried out using the method of experimental and statistical modeling. The damage to the microstructure of concrete was evaluated in two ways in order to obtain reliable information on structural parameters in the work. For each composition, 4 samples were studied, which were previously tested for ultimate tensile strength at bending. The damage factor is taken to quantify the damage. Mathematical models were built on average numerical values of concrete microstructure properties. Results. Analysis of statistical estimates of the composition of cement stone showed that the presence of linear particles improves the uniformity of the microstructure of decorative concrete. Correlation relationships of mean damage indices (determined by the second method) with physical and mechanical properties of the matrix material was revealed. However, it becomes necessary to determine rational dosages of recipe factors and optimal values of geometry of discrete fibers in order to achieve equivalent results, both in terms of damage and tensile strength during bending. Studies have confirmed that the average density, tensile strength during bending and the dynamic modulus of elasticity of the concrete microstructure are largely determined by the matrix damage. For its part, the amount of damage to the cement stone depends significantly on the initial water-cement ratio of the mixture. Changing the content of matrix and fiber modifiers allows managing damage and changing the nature of structural connections between discrete components of the composite. Originality. Regularities of individual and joint influence of modifiers and discrete fibers on structural and mechanical properties of concrete microstructure are established. Based on the experiments, it was shown that the use of zeolite in exchange for a part of cement and glass fiber in combination with polycarboxylate helps to reduce the damage to the concrete microstructure. Practical value. The use of the second method to determine the damage to the microstructure of the composite is rational in the study and analysis of physical and mechanical parameters of the integral structure of architectural products. The obtained results on the damage factor will allow us to recommend certain measures to reduce the damage to the concrete microstructure in order to ensure artistic and aesthetic expressiveness, operational reliability and technical and economic efficiency in architectural products.

Machine learning assessment of mechanical properties of oil palm shell concrete

Macroscopic and microscopic properties of alkali-activated ultra-high performance concrete at ambient and elevated temperatures: Effects of single and combined curing regimes

Study on the deterioration characteristics of physical-mechanical properties in pervious pavement concrete under hydrodynamic leaching action

Toward sustainable construction: A critical review of recycled aggregate concrete properties and future opportunities

The mechanical properties of M25 grade concrete, with partial replacement of cement by Silica fume andcoarseaggregate by over burnt bricks. Various concrete mixtures were prepared by replacing cement with Silica fume at varying percentages (0%, 8%, 9%, 10%, 11%, and 12%) and over burnt bricks replacement by coarse aggregate at varying percentage (0%, 15%, 20%, 25%, 30% and 35%) while maintaining the same water-cement ratio. The results shows that the inclusion of Silica fume improves the compressive strength and flexural strength due to the pozzolanic reaction and pore refinement, whereas the replacement of coarse aggregate with overburnt bricks reduces the density but maintains same strength.This study concludes that a combination of 10% Silica fume and 25% overburnt bricks aggregate provides an ecofriendly and cost-effective alternativefor sustainable concrete production without reducing the strength requirements of M25 grade concrete

The present study focuses on the utilization of saw dust as a partial replacement material for fine aggregate in concrete production. For the experimental investigation, Ordinary Portland Cement (53 Grade) was used, and fine aggregate was replaced with saw dust at varying proportions of 0%, 10%, 15%, and 20% by weight. The influence of saw dust on the workability and compressive strength of concrete was examined. Slump test was conducted to determine workability, while compressive strength tests were carried out at 7 days and 28 days of curing. The results indicate that the inclusion of saw dust up to 10% replacement produces satisfactory strength comparable to conventional concrete. However, higher percentages resulted in reduced workability and strength due to the lightweight and fibrous nature of saw dust. Hence, saw dust can be effectively used as a sustainable alternative to sand in non-structural and lightweight concrete applications

Synergistic effects of boiler ash and polypropylene fibers on the mechanical and durability properties of fly ash-based geopolymer foam concrete

Effect of recycled concrete waste on the improvement of physical, mechanical and microstructural properties of structural concrete

In this study, a thermal fatigue (TF) test for concrete in the temperature range of 20–80 °C was established, measuring mechanical properties and damage after 30, 60, 90, 120, and 150 TF cycles. Nano-scratching and high precision X-CT scanning methods were employed to reveal the evolution of micro fracture toughness and pore structure of concrete exposed to TF cycles. The results show that the mechanical properties of concrete were significantly decreased under TF cycles. In addition, the splitting tensile strength demonstrates the most striking deterioration among these mechanical properties, with a decrease of 34.8% after 150 TF cycles. The mean fracture toughness ( K c ¯ ) of the matrix and ITZ were decreased by 36.0 and 44.8% after 150 TF cycles. With the increase of TF cycles, the total porosity of concrete continuously increased, and pore structure degradation was dominated by the coarsening of pores larger than 0.01 mm3.

A major issue in industrial production is the generation of post-production wastes that are not biodegradable. The article presents an innovative solution for the management of industrial waste, which includes, among others, metal dust generated during the grinding of castings. The results of research on a concrete composite modified with metallic dust, a by-product from cast iron product manufacturing, were presented. The study analyzed the effect of using metallic dust as a partial replacement for fine aggregate at levels of 10%, 20%, 30%, 40%, and 50% on selected concrete properties. Tests included concrete mix consistency, compressive strength after 28 days and 6 months, density after 28 days of curing, bending strength, abrasion resistance using the Boehme disk method, durability in a salt chamber, and air content in hardened concrete. The research results indicate the possibility of using waste metal dust in concrete composites as a substitute for sand as a fine aggregate. An innovative waste processing solution allows the creation of a product with better abrasion resistance and compressive strength parameters while also having a good impact on the environment.

In the river environments of Xinjiang characterized by high sediment content and high flow velocities, hydraulic concrete is highly susceptible to damage from the impact and abrasion of bed load. Consequently, this imposes more stringent requirements on its mechanical properties and abrasion resistance. The incorporation of crumb rubber, a recyclable material, into concrete presents a dual benefit: it enables resource recycling while simultaneously offering a novel pathway for the development of concrete technology. This study takes rubber powder concrete as the research object. With the same water-to-binder ratio, rubber powder was incorporated at three volume fractions: 0%, 5%, and 10% of the cementitious material. The drop weight impact test and underwater steel ball method are adopted to evaluate its impact resistance and anti-scouring-abrasion performance, respectively. By testing the compressive strength, impact toughness, wear rate, anti-scouring-abrasion strength and three-dimensional morphological characteristics, the influence of rubber powder content on the mechanical properties and anti-scouring-abrasion performance of concrete is systematically analyzed. The research results show that the addition of rubber powder reduces the compressive strength of concrete, but significantly improves its impact resistance and anti-scouring-abrasion performance. Among all test groups, the concrete with 10% rubber powder content has the most significant decrease in compressive strength, with a decrease of about 37% compared with the 5% content group, while the 5% content group has a decrease of about 27% compared with the control group. However, its impact toughness at 3d, 7d and 15d is increased by about 84.7%, 88.4% and 84.4%, respectively, compared with the control group, showing the largest improvement range. At the same time, the wear rate of this group is reduced by about 42.5%, and the anti-scouring-abrasion strength is increased by about 61%. Combined with the three-dimensional morphology analysis, it can be seen that the specimens in this group exhibit the optimal anti-scouring-abrasion performance. In terms of microstructure, the porosity of rubber powder concrete increases, the generation of C-S-H gel decreases and its continuity is damaged, leading to a significant decrease in compressive strength. The reduction in the generation of delayed ettringite enhances the toughness and anti-scouring-abrasion performance. In general, the increase in rubber powder content will lead to a decrease in the compressive strength of concrete, but within a certain range, it can significantly improve its impact resistance and anti-scouring-abrasion performance. Crumb rubber effectively enhances the impact and abrasion resistance of hydraulic concrete, demonstrating strong application potential in high-flow, sediment-laden river environments.

As the volume of reinforced concrete structures continues to grow, it is important to determine the quality of concrete in the shortest time possible. Therefore, the development and validation of methods for non-destructive testing (NDT) of concrete structures are becoming increasingly important. However, some factors may affect the accuracy of the measurement results obtained as concrete is often exposed to a moist environment, e.g., in marine structures. Ignoring these factors may lead to an inaccurate interpretation of measurements. Therefore, in this research, the water saturation factor of concrete was investigated in response to various NDT methods. C25/30 and C40/50 MPa concrete were evaluated using ultrasonic pulse velocity and rebound hardness devices, and for the first time, a drilling resistance (DR) method was systematically adapted and validated for moisture-affected concrete testing. Unlike conventional approaches that only consider surface effects, the DR method introduced here provides in-depth profiling of concrete, revealing variations in resistance with depth and identifying zones influenced by internal moisture distribution. This study demonstrates that the DR method can complement traditional NDT techniques, providing a more reliable evaluation of moisture-induced variations in concrete properties. Moreover, with the novel DR method, changes in the mechanical response with depth have been quantified, offering new insight into internal moisture effects that are not accessible by conventional NDT methods.

Nanotechnology has emerged as a transformative approach to enhancing the concrete properties. This research examines the impact of nano-titanium dioxide (NT) on the concrete properties. NT was incorporated in varying dosages (0.5%, 1%, and 1.5% by weight of the cement) to assess its impact on strength, toughness, and resilience. The results demonstrated a significant enhancement in mechanical properties, with a peak compressive strength of 65.20 ± 1.03 MPa, a split tensile strength of 3.44 ± 0.17 MPa, and a flexural strength of 9.5 ± 0.47 MPa at a 1.5% NT dosage after 28 days of curing. Furthermore, the long-term performance was notable, as the compressive strength further increased to 75.25 ± 1.10 MPa at 180 days, confirming the sustained strength-gain potential of NT-incorporated concrete. Also, durability assessments were conducted under aggressive conditions, including exposure to 4% NaCl, HCl, and H2SO4 for 90 days. Additional tests, including rapid chloride penetrability test (RCPT), surface resistivity, freeze-thaw resistance, and accelerated carbonation, were conducted to assess long-term durability along with its economic feasibility. The NT-incorporated concrete demonstrated enhanced resistance to chloride ingress, acid attack, and elevated temperatures (200–600 °C), with improved modulus of elasticity and fire resistance. Furthermore, durability assessments revealed a noteworthy contrast, i.e., while resistivity tests classified NT-incorporated concretes as having ‘very low’ chloride penetrability, RCPT values remained in the ‘moderate’ category. This divergence underscores the need for multiple durability indices in evaluating nano-concretes. Microstructural analyses using scanning electron microscopy confirmed the densification effect of NT, leading to a refined pore structure and improved bond efficiency within the cementitious matrix. Moreover, economic analysis confirms the economic viability of nano-titanium concrete, demonstrating significant long-term savings through service life extension despite higher initial investment. This research highlights the potential of NT in developing high-performance, durable concrete, reinforcing the importance of nanotechnology in construction industry.Supplementary InformationThe online version contains supplementary material available at 10.1038/s41598-025-22974-4.

Emerging Supplementary Cementitious Materials: A Comprehensive Review of Material Properties, Reactivity and Impact on Concrete Properties

This study explores the mechanical behavior of concrete reinforced with recycled carbon fiber (RCF) and incorporating modified basic oxygen furnace slag (MBOF) as a sustainable aggregate. The RCF was recovered from waste carbon fiber-reinforced polymer (CFRP) bicycle rims via microwave-assisted pyrolysis (MAP), while MBOF was produced by water-based treatment of hot BOF slag. The experimental program included compressive, splitting tensile, and flexural strength tests, as well as impact resistance and stress-reversal Split Hopkinson Pressure Bar (SRSHPB) tests. The effects of RCF length (6 mm and 12 mm) on the mechanical performance of MBOF-based concrete were systematically examined. The results demonstrated that incorporating MBOF as aggregate, combined with the addition of RCF, significantly enhanced both static strength and dynamic impact resistance. Compared with fiber-free MBOF concrete, the incorporation of 6 mm and 12 mm RCF increased compressive strength by 3.03% and 13.77%, flexural strength by 14.50% and 19.74%, and splitting tensile strength by 2.60% and 25.84%, respectively. Similarly, the impact number increased by approximately 6.81 and 12.67 times for the 6 mm and 12 mm RCF specimens, respectively, relative to the fiber-free specimen. Furthermore, the SRSHPB test results indicated that MBOF concrete reinforced with 12 mm RCF exhibited greater dynamic compressive strength than that reinforced with 6 mm RCF. Overall, MBOF concrete incorporating 12 mm RCF demonstrated superior performance to its 6 mm counterpart across all evaluated strength parameters. These findings highlight the potential of utilizing metallurgical and composite waste to develop high-performance, sustainable concrete materials.

The impact of incorporating chopped basalt fibers into the mixture on some mechanical properties of concrete

The recycling of waste materials as environmentally friendly cement alternatives to lessen the impact of CO2 emissions and safeguard natural resources associated with cement manufacturing cannot be over-emphasized. This study investigates the effects of recycled waste materials such as shea nutshell ash and ground oyster seashell as Portland limestone cement substitutes on the mechanical, durability, and sustainability performances of ternary blended concrete. Shea nutshell ash and ground oyster seashell were partially used as cement replacement at 5–15 wt. % and tested for mechanical properties after 3–120 curing ages. Chemical resistances and drying shrinkage were conducted as durability performance after 120 and 1–120 curing ages. The results revealed higher compressive, flexural, and split tensile strengths at later ages, with about a 3% increase at 10 wt. % substitution after 90 curing ages than the control concrete. Ternary blended concrete samples, at 5–10 wt. % of shea nutshell ash and ground oyster seashell replacement levels, resulted in improved acidic, sulfate, and drying shrinkage resistances by 11–40%, 12–53%, and 9–34%, compared to the control samples. Ultimately, this research recommends an optimum of 10 wt. % shea nutshell ash and ground oyster seashell as cement alternatives, enhancing mechanical durability properties of ternary blended concrete.

The use of artificial aggregates manufactured from waste and by-product materials, as an alternative to natural aggregate, has attracted considerable research interest. Extensive research has been conducted to pre-process or pre-treat different source of wastes to be used as raw materials for artificial aggregates (AAs) production. In this experimental work artificial aggregates have been manufactured by means of cold-bonding granulation. Cold-bonding pelletization is carried out through a rotating plate device allowing the formation of pelletized aggregates from waste materials through gravitational and centrifugal forces. In addition to traditional single step cold bonding granulation, a double pelletization was carried out to obtain AAs with improved properties. In the one-step pelletization process the waste is incorporated within the binding matrix, while the two-step procedure involves a second encapsulation to obtain AAs embedded within an outer shell, likely able to improve their physical properties. Several concrete mixtures were designed by alternatively adding either single-bond or double-bond AAs at different dosages (0% - 10% - 20% and 30% replacement by weight of aggregate). Then, several Artificial Aggregate Concretes (AACs) specimens were manufactured and characterized in terms of fresh and hardened concrete properties. In detail, in addition to fresh consistency tests, density evaluations were carried out at fresh and hardened state; compression, indirect tensile and bending tests were performed at both early age and long term. All AACs, including those prepared with 30% double-bond pelletization aggregates, achieved adequate mechanical performances to be used in structural concretes.