Conventional Cementitious Materials Research Articles

Performance Study on Laterite Block with Perlite

Abstract The term “perlite” refers to an amorphous volcanic silicate/alumina rock that can expand at temperatures between 900 and 1200 ∼C when heated fast. Because perlite is so versatile, it can be applied in a variety of sectors, including construction, horticulture, petrochemical, and industrial. An item that is used in the construction sector is expanded perlite (EP). It can be used as an input for geopolymers or mixed with aggregate or cement to create conventional cementitious materials. EP offers low density, effective thermal and acoustic insulation, and exceptional fire resistance for buildings. Perlite appears to be a necessary material as a result. The author of this article examines the effects of EP, a chemical used in building materials, on the properties of geopolymers, different types of binder, and regular cementitious materials, both in their fresh and hardened states. The usefulness of using perlite-reinforced laterite blocks as a sustainable building material is investigated in this work. We investigate this composite’s potential for usage in building applications by thoroughly examining its mechanical and thermal properties. The results provide insight into how robust and eco-friendly construction practices could be supported by increasing structural strength and thermal efficiency.

Evaluating the pozzolanic activity of andesite and calcined marl for high-performance concrete: a valorization of algerian mineral resources

This study evaluates the pozzolanic activity of andesite and calcined marl sourced from Algeria for potential use as supplementary cementitious materials. The research addresses the need for sustainable construction practices by leveraging local mineral resources. The objectives include assessing the pozzolanic properties of these materials and their effects on mortar mixes. The methodology involves collecting samples from specific quarries, crushing and grinding them into fine powders, and calcining the marl at 750°C. The materials were characterized using X-ray diffraction (XRD), X-ray fluorescence (XRF), and scanning electron microscopy (SEM). Pozzolanic activity was evaluated through Frattini and Saturated Lime Tests, followed by mortar mix analyses with varying substitution levels. Results indicated that andesite and calcined marl exhibit significant pozzolanic activity, with andesite showing the highest reactivity. The inclusion of these additives improved the formation of calcium silicate hydrate (C-S-H) and reduced portlandite content, enhancing the durability and mechanical properties of the mortar. The study concludes that these local mineral resources are viable alternatives to conventional cementitious materials, promoting sustainability in the construction industry.

Rheological properties and dry-cracking resistance of cementitious materials modified by CNFs doping

With the continuous development of building material science, modified cementitious materials have become a popular research direction. Carbon nanofibers, because of their unique properties, their application potential is shown in the construction field. To raise the rheological properties and dry-cracking resistance of cementitious materials, this study used mechanical shear method to prepare carbon nanofibers with different dosages. Subsequently, the rheological properties, compressive properties and dry cracking resistance of cementitious materials with different dosages were tested to obtain the optimal values of carbon nanofibrillated cellulose dosage. The study compared the application effect of the modified cementitious materials with that of the conventional cementitious materials. The experiment outcomes indicated that the highest shear stress of 118.7 Pa was observed in the cementitious material with 0.2 % carbon nanofibrillated cellulose dosage at 0.5 water-to-cement ratio, and the most significant reduction of self-shrinkage of 0.1 % carbon nanofibrillated cellulose dosage was observed in the cementitious material with a self-shrinkage reduction of 0.76. In addition, carbon nanofibrillated cellulose-based cementitious materials also showed good practical application effects. The above results indicate that carbon nanofibrillated cellulose can provide better performance for cementitious materials, which provides new possibilities for the development of high-performance cementitious materials.

Spring-like behavior of cementitious composite enabled by auxetic hyperelastic frame

A novel highly compressible auxetic cementitious composite (ACC) is developed in this work. Contrary to conventional cementitious materials, such as plain concrete and fiber reinforced concrete, the ACC shows strain-hardening behavior under uniaxial compression: the stress continuously increases with strain up to approximately 40 % strain. On one hand, in the early compression stage, the ACC exhibit highly recoverable deformability of 10 % strain under cyclic loading (20 times higher than the constituent cementitious material). In addition, the ACC shows fatigue damage until the stiffness/strength and energy dissipation plateau values are reached after 500 cycles. At 2.5 % strain amplitude, the plateau stiffness/strength is approximately 120 MPa/3 MPa, while these values are only 25 MPa/1.2 MPa at 5 % strain amplitude. In contrast, the energy dissipation plateau of the ACC is independent from the amplitude and remains at 0.05 J/cm3. On the other hand, due to the strain-hardening behavior, the ACC exhibits significantly improved energy dissipation capacity compared to both the conventional cementitious materials and the auxetic frame. This behavior is achieved by a tailored composite action: integrating cementitious mortar with 3D printed thermoplastic polyurethane (TPU) auxetic frame. A rotating-square auxetic mechanism was designed for the TPU frame for the ACC to achieve the tailored cracking behavior. The horizontal ACC cells enable large deformability by enlarging the crack width under the confinement of the auxetic frame, while the vertical cells work as stiffening phase to ensure load resistance. Owing to the outstanding mechanical properties, the ACC shows great potential to be applied in engineering practice where high compressive deformability is required, for instance yielding elements for squeezing tunnel linings.

Synergistic effect of combining low kaolinite grade calcined clay with conventional cementitious materials

Synergistic effect of combining low kaolinite grade calcined clay with conventional cementitious materials

Advancements in Soil Stabilization: The Efficacy of Fly Ash and GGBS

Engineered soil qualities can be modified mechanically, chemically, or biologically to achieve soil stabilisation. Soil stabilisation is a method used in civil engineering to enhance and enhance a soil’s structural qualities. Mechanical strength, permeation, compressibility, resilience, and plasticity are some of these attributes. The systematic investigation of soil stabilization with fly ash and ground granulated blast furnace slag (GGBS) as binders is presented in this work. The goal of using geopolymer technology is to enhance the mechanical qualities of clay soils for the building of road pavement by substituting conventional cementitious materials. The ideal ratio of Fly Ash to GGBS is found using a Taguchi experimental design technique, more precisely a L9 Orthogonal Array, with the goal of improving soil liquid limit, plastic limit, and plasticity index. The effectiveness of various Fly Ash and GGBS ratios is assessed, as well as their influence on soil behavior. In order to develop models for predicting soil parameters, regression analysis is used. Diagnostic plots show a reasonable fit but also highlight small amounts of unexplained variability. These discoveries have important ramifications for sustainable construction methods and are essential for improving soil stabilizing procedures, especially when it comes to road pavement engineering.

Evaluating lithium slag for geopolymer concrete: A review of its properties and sustainable construction applications

This comprehensive review paper evaluates lithium slag (LS) as a promising precursor for geopolymer concrete, focusing on its workability, strength, durability, and microstructure. In the context of sustainable construction, LS emerges as a vital alternative to conventional cementitious materials, primarily due to the environmental concerns associated with cement production, such as substantial greenhouse gas emissions and air pollution. Geopolymer technology utilizes alkali activators and aluminosilicate-rich materials, offers a reduced environmental footprint and shows comparable performance to traditional cement-based concrete. In particular, LS has gained attention for its potential as an aluminosilicate precursor material in geopolymer concrete. This review investigated the recent advancements in LS-based geopolymers, exploring various processing techniques like mechanical activation, calcination, and chemical treatment to optimize LS geopolymerisation and enhance early strength development. The incorporation of binary/ternary aluminosilicate material is also discussed, aiming to improve crucial properties such as workability, strength, durability, and microstructure. The needs for comprehensive research into LS-based geopolymers to achieve their full potential in sustainable construction, promoting an environmentally friendly approach and contribution to a circular economy in the construction industry are highlighted.

3D auxetic cementitious-polymeric composite structure with compressive strain-hardening behavior

A composite can have properties much better than the components it is made of. This work proposes a three-dimensional auxetic cementitious-polymeric composite structure (3D-ACPC) which incorporates 3D printed polymeric shell with cementitious mortar. Uniaxial compression experiments are performed on the 3D-ACPC to study their quasi-static stress-strain response. Experimental results show that the created composite structure can simultaneously overcome the brittleness of conventional cementitious material and the low compressive strength of 3D printed polymeric cellular shell. Therefore, the 3D-ACPC exhibit compressive strain-hardening behavior ensuring high energy absorption ability. In addition, it is found that structural anisotropy and the shell printing direction have significant impact on the stress-strain response of the 3D-ACPC. Moreover, due to the lightweight cellular structure, the 3D-ACPC shows significantly enhanced specific energy absorption compared to conventional cementitious materials and polymeric cellular materials. To this end, the developed 3D-ACPC has great potential to be used in engineering practice, such as protective structures.

Mechanical and Physical Performance of Portland Cement Composites with Partial Replacements of Metakaolin and Ulexite

Fabricating green binding materials are gaining a great importance in the construction sector recently. This rising interest is based upon the need for more sustainable and environment-friendly alternatives to conventional cementitious materials by utilizing waste materials and mineral by-products in the binding matrices through partial or complete replacement with Portland cement. In this paper, an experimental investigation was conducted to examine the effect of using a boron waste, namely ulexite, along with metakaolin as partial replacements with Portland cement. By this means, flow table, setting time, compressive and flexural strengths, unit weight, water absorption, and porosity tests were carried out on twelve different specimens, including the amount of ulexite of 5% and 7%, metakaolin of 10% and 20%, and amount of superplasticizer additive of 1%. The main conclusions of this work showed that using ulexite and metakaolin up to certain percentages is beneficial in terms of mechanical and physical properties. A further increase in the addition can lead to a decrease in the performance of the matrix.

Impact and durability properties of alccofine-based hybrid fibre-reinforced self-compacting concrete

Many research works have already been made and are still in progress on metallic fibres, as their incorporation reduces the brittleness of the concrete and improves its resistance to the impact and crack propagation. But the use of such non-metallic fibres may induce corrosion which is a major problem to be addressed from the durability aspect. To overcome this problem, in the present research work, a non-metallic hybrid fibre combination was investigated with synthetic fibres like polypropylene and abaca fibres. Also, rather than using conventional cementitious materials such as silica fume, fly ash, and ground granulated blast furnace slag, a new generation of ultra-fine material namely alccofine was used as a partial replacement for the cement by 15%. Abaca fibre was utilised in a constant addition of 0.5% and blended with polypropylene fibre in a range varying from 0% to 2% with an increment of 0.5%. The fresh properties of self-compacting concrete (SCC) in mono and hybrid fibres combinations were assessed through slump flow, J-ring, and V-funnel tests. Water absorption and sorptivity tests were conducted to ensure the durability of the prepared mix. Further, impact tests were carried out on the prepared cylinder specimens to check the capability of the mix with the non-metallic hybrid combination. The main objective here was to check whether a high-strength durable SCC could be achieved using non-metallic fibres and natural fibres. From the obtained experimental results, it was observed that 15% alccofine as a partial substitute to the cement with the addition of 0.5% of abaca fibre and 2% of polypropylene fibre to SCC performed better than the control SCC.

The Effect of Natrium Hydroxide Molarity Variation and Alkali Ratio on the Compressive Strength of Geopolymer Paste and Mortar

Geopolymers have great potential to replace conventional cementitious materials and are classified as green materials. Their main constituents are silica (Si) and aluminum (Al), which can be found in the fly ash material from industrial processes of the PLTU. The parameters that affect the strength of the concrete are influenced by the molarity of natrium hydroxide and the ratio of alkalis (NaOH/Na2SiO3). This study examined the characteristics of the geopolymer paste and mortar specimens. Furthermore, mixture composition was carried out using the weight ratio method. The mortar produced consists of 65% fine aggregate and 35% paste, while the pasta contains 60% fly ash and 40% alkaline solution. The molarities of NaOH used were 8M, 10M, 12M, and 14M with a base ratio of 1.5, 2, and 2.5 Na2SiO3/NaOH. The curing of specimens was carried out with the humid temperature method. The results showed that the highest compressive strength of geopolymer paste and mortar was obtained at 12M NaOH molarity with an alkaline ratio of 2.5, namely 12.59 MPa and 21.75 MPa at 28 days, respectively. NaOH of more than 12M can cause a decrease, while the base ratio of 2.5 has the highest strength. The results also showed that the higher the molarity of NaOH and the greater the alkaline ratios, the longer the setting time.

Review of the Interactions between Conventional Cementitious Materials and Heavy Metal Ions in Stabilization/Solidification Processing.

In the past few decades, solidification/stabilization (S/S) technology has been put forward for the purpose of improving soil strength and inhibiting contaminant migration in the remediation of heavy metal-contaminated sites. Cement, lime, and fly ash are among the most common and effective binders to treat contaminated soils. During S/S processing, the main interactions that are responsible for improving the soil's behaviors can be summarized as gelification, self-hardening, and aggregation. Currently, precipitation, incorporation, and substitution have been commonly accepted as the predominant immobilization mechanisms for heavy metal ions and have been directly verified by some micro-testing techniques. While replacement of Ca2+/Si4+ in the cementitious products and physical encapsulation remain controversial, which is proposed dependent on the indirect results. Lead and zinc can retard both the initial and final setting times of cement hydration, while chromium can accelerate the initial cement hydration. Though cadmium can shorten the initial setting time, further cement hydration will be inhibited. While for mercury, the interference impact is closely associated with its adapted anion. It should be pointed out that obtaining a better understanding of the remediation mechanism involved in S/S processing will contribute to facilitating technical improvement, further extension, and application.

Elimination of Greenhouse Gas Emissions by Utilization of Industrial Wastes in High Strength Concrete for Environmental Protection

Greenhouse gases prevalence in the atmosphere is a primary reason for global warming. The cement manufacturing sectors are a significant producer of greenhouse gases, contributing one metric tonne of carbon dioxide into the environment for every metric tonne of cement produced. The heat of concrete is increased by several degrees during the pozzolanic reaction, and CO2 is released. The development of binary and ternary cementitious systems has minimized the unfavorable reactions of conventional cementitious materials. Metakaolin and alccofine, two mineral admixtures derived as waste products from industries, were used as cement substitutes in this study. The compressive strength of alccofine was compared to a metakaolin-based high strength eco-friendly concrete mix of grade M50 in an experimental investigation. In the case of binary and ternary blended cementitious systems with alccofine and metakaolin, twelve alternative mix proportions were tested, ranging from 0 to 20% in 5% increments. Based on the observed mechanical characteristics of concrete, it was discovered that the optimum replacement of alccofine was 15% and metakaolin was 5% by volume of cement in the binary cementitious system. Similarly, in the ternary cementitious system, replacing 15% alccofine with 5% metakaolin in the cement mixture results in the greatest increase in compressive strength when compared to the other experiments. As a result, it is concluded that using extra cementitious materials in concrete with mineral admixtures such as alccofine and metakaolin results in significant cost and energy savings, as well as a notable reduction in environmental pollution.

Production of green bricks from low-reactive copper mine tailings: Durability and environmental aspects

In response to the net-zero emissions plan for 2050, geopolymerization of mine tailings (MT) has attracted massive attention from construction material researchers and engineers. To successfully recycle or reuse MT through geopolymerization, it is essential to have a reliable understanding of the environmental and durability aspects of the geopolymer products. This study investigates the durability and leaching behavior of geopolymer bricks produced from low-reactive copper MT as the primary aluminosilicate precursor and slag as the supplementary cementitious material (SCM). Durability tests include fourteen (14) wet-dry cycles and fifty (50) freeze–thaw cycles, respectively. After the durability test, the weight loss and unconfined compressive strength (UCS) of the geopolymer brick specimens were measured. The leaching study was conducted following TCLP guidelines by immersing the geopolymer brick specimens in solutions with pH = 4 and 7, and measuring the concentration of contaminants in the solution after 120 days. After the leaching test, the wet and dry UCS of the geopolymer specimens were measured. In addition, microscopic studies including SEM/EDX and XRD were performed to study the microstructural changes and the phase composition. The results show a substantial loss in UCS after the durability tests. However, the weight loss is small compared with conventional cementitious materials. Most importantly, the contaminants in the MT are successfully stabilized within the geopolymer framework.

The Influence of Sintering Temperature on the Pore Structure of an Alkali-Activated Kaolin-Based Geopolymer Ceramic.

Geopolymer materials are used as construction materials due to their lower carbon dioxide (CO2) emissions compared with conventional cementitious materials. An example of a geopolymer material is alkali-activated kaolin, which is a viable alternative for producing high-strength ceramics. Producing high-performing kaolin ceramics using the conventional method requires a high processing temperature (over 1200 °C). However, properties such as pore size and distribution are affected at high sintering temperatures. Therefore, knowledge regarding the sintering process and related pore structures on alkali-activated kaolin geopolymer ceramic is crucial for optimizing the properties of the aforementioned materials. Pore size was analyzed using neutron tomography, while pore distribution was observed using synchrotron micro-XRF. This study elucidated the pore structure of alkali-activated kaolin at various sintering temperatures. The experiments showed the presence of open pores and closed pores in alkali-activated kaolin geopolymer ceramic samples. The distributions of the main elements within the geopolymer ceramic edifice were found with Si and Al maps, allowing for the identification of the kaolin geopolymer. The results also confirmed that increasing the sintering temperature to 1100 °C resulted in the alkali-activated kaolin geopolymer ceramic samples having large pores, with an average size of ~80 µm3 and a layered porosity distribution.

Performance and sustainability overview of sodium carbonate activated slag materials cured at ambient temperature

The production of Portland cement (PC) which is the main binder in conventional cementitious materials contributes about 7% to the world’s anthropogenic carbon dioxide emission. As the demand for PC is expected to increase significantly in the coming years, it is imperative to find other environmentally friendly alternatives. Alkali-activated binders (AABs) obtained by alkali activation of aluminosilicate precursors are viable alternatives for PC as they possess lower embodied carbon and energy compared to PC. However, the conventional activators (i.e. sodium silicate and sodium hydroxide) are corrosive, expensive and have a high environmental footprint. These limitations have resulted in impractical and expensive applications of such binders on a large scale. On the other hand, sodium carbonate, which is less corrosive, cheaper and available naturally in the environment can be used as a sustainable alternative to sodium silicate and sodium hydroxide. In a quest to propel the application of sustainable binders, this study was undertaken to explore the properties of slag activated with sodium carbonate at ambient temperature. The effect of sodium carbonate dosage on the fresh, mechanical and durability properties are discussed. A simplified sustainability assessment of concrete made with different binders was also carried out and the results showed that the sodium carbonate activated slag concretes are a sustainable alternative to PC concrete to achieve a cleaner environment. • Sodium carbonate was used as an activator in alkali-activated slag systems. • Sodium carbonate activated slag can be used as an alternative to Portland cement. • Materials made with sodium carbonate activated slag exhibited good properties. • Sodium carbonate is more eco-friendly compared to sodium silicate/hydroxide.

Curing process and pore structure of metakaolin-based geopolymers: Liquid-state 1H NMR investigation

Geopolymers are emerging construction materials with lower carbon dioxide emissions compared to the conventional cementitious materials. The knowledge of the curing process and the related pore structures are important for optimizing the properties of these materials for different applications. The curing process and final pore structure are sensitive to the amount of used water, however the specifics are unclear. The curing process and pore structures of metakaolin-based geopolymers with a narrow water-to-solid (w/s) ratio (0.59–0.66) were monitored by nuclear magnetic resonance (NMR) relaxometry and cryoporometry. The 14-day curing process was investigated by monitoring the change of T2 and T1 relaxation times and water signal intensity. After the curing, the pore structures were characterized by 2D T1-T2 correlation and T2-T2 exchange measurements of absorbed water. The pore size distributions (PSDs) were measured with NMR cryoporometry and compared to nitrogen physisorption and mercury intrusion porosimetry (MIP) results. We found that the relaxation times decreased as the pore structure of the geopolymers matured during the curing while the dissolution and the condensation periods of the curing were distinguished by the changes in signal amplitude reflecting the proton density. After the curing, three distinct pore sizes and connectivity between pores were identified from T1-T2 and T2-T2 spectra. Their PSDs were measured, and they were found to correspond to two different pore sizes originating from the arrangement of clusters and defective pores. In the narrow w/s ratio (0.59–0.66), the curing times were the same for all samples when cured at 24 °C while the pore sizes were observed to increase as a function of the w/s ratio.

Smart Cementitious Composites for Road Traffic Monitoring and Weighing in Motion

The addition of electrically conductive materials at micro scale, such as carbon fibres (CF) or steel fibres (SF), to conventional cementitious materials makes piezo-resistive behaviours possible in terms of changes in electrical resistivity due to applied stresses. Smart cementitious composites (SCCs) may thus be able to detect traffic density and sense weight in motion thanks to such piezo-resistive property. Three types of cement-based sensors, with CF, SF, or a hybrid of CF and SF, were experimentally evaluated by applying quasi-static and dynamic load cycles after seven days of curing in different load directions reflecting the electrodes and different circuit type connections of the specimens. The performance of each type of sensor was assessed based on measuring the changes in electrical resistivity (ER) under compressive and flexure stresses, with test results revealing that the use of CF in these composites was the best choice because this generated more sensitivity to applied loads in terms of the change in ER compared with other types. These results were achieved when the applied load was parallel to the electrode direction. The findings also indicated arrangement of specimens as an electric series circuit type was the best setup configuration for traffic monitoring and weight in motion measurement.

Valorization of glass powder waste, crushed and dune sands in the mix design of ultra-high performance fiber reinforced concrete: Assessing effect of waste variability

This work deals with the valorization of industrial glass waste as supplementary cementitious materials in Ultra High Performance Fiber-Reinforced Concrete (UHPFRC). It aims to take advantage of this type of by-product in order to improve both fresh and hardened performances of conventional cementitious materials. This study concerns the use of glass powder originating from different locations with slight variation in their chemical composition (named transparent, smoked, and opaque) as a supplementary cementitious material (substitution ratio: 20% of the cement weight). Series of standardized tests were performed to characterize the influence of these glass powders on both fresh state properties (slump flow) and hardened state properties of tested UHPFRC. Mechanical properties are measured after cure periods lasting from 2 to 28 days. The study on the microstructure of hardened concrete was made using scanning electron microscopy and water penetration. Obtained results show the beneficial effect brought by the addition of a significant dosage of glass powder (here 20% of the cement weight) on the behavior of concrete in its fresh and hardened state.

Cementitious cellular composites with auxetic behavior

Auxetic behavior refers to material with negative Poisson's ratio. In this research, a new type of cementitious auxetic material is developed. A novel crack bridging auxetic mechanism is discovered which is in contrast with a local buckling mechanism commonly employed to trigger auxetic behavior. Taking advantage of 3D printing techniques, cementitious cellular composite (CCC) specimens with auxetic cellular structures were produced. Meanwhile, cementitious materials with different fiber content were used as constituent material. Uniaxial compression and cyclic loading tests were performed on the CCCs. Experiments show that with proper constituent material, CCCs can exhibit auxetic behavior which is induced by crack bridging process of the cementitious constituent material. In addition, strain hardening behavior can be identified in the stress-strain curve under uniaxial compression and consequently high specific energy absorption is obtained. Furthermore, 2.5% of reversible deformation which is significantly higher than conventional cementitious materials under cyclic loading is obtained within 25,000 cycles. Obvious fatigue damage is observed in the first 3000 cycles, afterwards signs of mechanical properties recovering can be found. The discovered auxetic mechanism indicates a new designing direction for brittle materials to achieve auxetic behaviors.