Exploring the potential of agricultural waste as an additive in ultra-high-performance concrete for sustainable construction: A comprehensive review

Hakeem I.Y., Amin M., Agwa I.S., Abd-Elrahman M.H., Abdelmagied M.F.

Today, recycling and the use of eco-friendly construction supplies are major concerns for the environment. Concrete is frequently utilized in the engineering and construction sectors. In the past several decades, ultra-high performance concrete (UHPC), characterized by very high mechanical qualities, has emerged as one of the most popular types of concrete. Huge quantities of Ordinary Portland cement (OPC) are often utilized; this increases the price of UHPC, limits its widespread usage in structural applications, produces a substantial quantity of carbon dioxide, and uses a sizable amount of natural resources. It is recommended that other additives be used in lieu of OPC in concrete preparation and that recycled aggregates from a variety of sources be used in place of natural aggregates to make UHPC production more environmentally friendly and economically feasible. This study combines industrial and agricultural waste to create an affordable and sustainable UHPC. For example, glass particles (GP) as a manufacturing byproduct generated by glass waste (GW) are utilized as an alternative for fine aggregate "sand (S)" with substitution ratios of 0 %, 50 %, and 100 %, while wheat straw ash (WSA), as an agricultural byproduct, is utilized as an OPC substitute at varying substitution ratios 0 %, 10 %, 20 %, and 30 %. We conducted and analyzed experiments with 12 mixtures divided into three groups. Several factors are studied, including slump flow, mechanical characteristics, drying shrinkage, high temperature, and microstructural features. Based on the obtained outcomes, boosting the percentage of GP utilized to substitute the S made it more workable. In addition, replacing 20 % of the OPC with WSA and 0 % of the S with GP yielded the best results in terms of mechanical characteristics. Increasing the WSA replacement rate while fixing GP to S substitution level significantly reduced drying shrinkage values. Lastly, the compressive strength (fc) findings of UHPC structural components exposed to elevated temperatures up to 200 °C were enhanced using GP as a replacement for S. In brief, the results of this experimental investigation can contribute well to illustrating the effect of utilizing GP and WSA to manufacture sustainable ultra-high-performance concrete.

Hakeem I.Y., Amin M., Agwa I.S., Abd-Elrahman M.H., Ibrahim O.M., Samy M.

Egypt produces more rice straw than any other nation, and this residue is currently discarded in untreated landfills and open fields, causing environmental damage in the country. Furthermore, eggshells, a waste product used in bakeries, restaurants, and poultry farms, were typically disposed of in landfills, posing health hazards. So, grinding eggshells into nanoparticles, known as nano eggshell powder (NEP), increases its activity. In addition, to its high calcium content, NEP may be used with pozzolanic substances like rice straw ash (RSA), which have a lower calcium concentration. This study examined the characteristics of ultra-high-performance concrete (UHPC) produced using RSA and NEP eco-friendly components within partial cement substitution. The ratios of RSA to cement were 0%, 10%, 20%, and 30%, while the NEP quantities were 2, 4, and 6% of the total binder. The results indicate that combining NEP and RSA as pozzolanic materials can improve concrete characteristics while decreasing cement content and reducing environmental contamination. Using RSA and NEP as substitutes for cement has also improved the material's mechanical characteristics, durability, and dry shrinkage.

Hakeem I.Y., Amin M., Agwa I.S., Rizk M.S., Abdelmagied M.F.

A significant quantity of cement is necessary for the production of ultra-high-performance concrete (UHPC). However, some environmental issues are associated with cement production. The worldwide agricultural growth increases ash from agricultural waste (AW). Furthermore, industrial waste (IW) generated throughout the stone-cutting and processing has increased due to the growing demand for granite stone in construction. This research conducted a unique study that involved comparing the use of sugarcane leaf ash (SLA) as AW and granite dust (GD) as IW as partial substitutes for cement in the production of eco-friendly UHPC. The effect of employing SLA and GD with replacement ratios ranging from 20% to 50% on the mechanical and transport properties of UHPC was studied. In addition, this research investigated the effectiveness of partial replacement of natural fine aggregate (NFA) by recycled fine aggregate (RFA) with ratios ranging from 25% to 100% on the UHPC qualities. Moreover, the effect of elevated temperatures on the UHPC and the microstructural examination were investigated. Results demonstrated that the optimum replacement ratio of SLA or GD from cement was 20%, showing the best mechanical characteristics of the UHPC. For example, after 28 days of casting, the compressive strength increased by 12.16% and 8.44% when SLA and GD were added to the UHPC mix, respectively. Additionally, the 25% replacement ratio of RFA from NFA presented the best mechanical and transport properties of the UHPC. The mixes containing SLA positively affected the UHPC higher than those containing GD.

Hamada H., Abed F., Alattar A., Yahaya F., Tayeh B., Aisheh Y.I.

In recent days, the increase in significant infrastructure projects has led to urgent requirements for the use of high strength concrete (HSC) and ultra-high-performance concrete (UHPC). However, the use of cement and its derivative products, such as concrete, is associated with a high generation of carbon dioxide (CO2). The construction industry contributes about 8% of the total global CO2 production. Therefore, there is an urgent need to use agriculture-waste materials such as palm oil fuel ash (POFA) to help reduce environmental concerns associated with concrete. The accumulation of palm oil waste over an extended period of time causes environmental pollution. The use of these materials is expected to improve the environment by reducing the disposal of this waste in landfills and open areas. The chemical composition of POFA can vary depending on the source and processing methods. Elevated levels of impurities such as organic matter, unburned carbon, and chloride content in POFA can adversely affect the setting time, workability, and long-term durability of concrete. The optimal mix proportioning and replacement levels of POFA in concrete need to be carefully determined. Incorporating higher levels of POFA without proper adjustments to the mix design can result in detrimental effects on fresh and hardened concrete properties, including reduced compressive strength and decreased resistance to chemical attacks. This paper will highlight the impacts of POFA on the properties of HSC and UHPC in their fresh and hardened states. Durability and microstructure properties were also discussed. The use of ultrafine POFA helped in reducing the rapid chloride permeability and water absorption of HSC, thus improved its structure. Lastly, some recommendations for future studies are presented.

Alyami M., Amin M., Zeyad A.M., Tayeh B.A., Hakeem I.Y., Agwa I.S.

The accumulation of agricultural waste is a growing environmental problem in many countries. Therefore, this study focuses on the assimilation of large quantities of agricultural waste ash as a partial substitute for Ordinary Portland Cement (OPC) to produce Sustainable Ultra High-Performance Concrete (SUHPC). Local agricultural residue ash from rice husk (RHA), sugarcane leaf ash (SLA), and olive waste ash (OWA) were used to replace 50% of the weight of the OPC. Sixteen mixtures were prepared by replacing the OPC with agricultural residue ash of RHA, SLA, and OWA at 0%, 10%, 20%, 30%, 40%, and 50% by weight. The effect of using RHA, SLA, and OWA on the properties of UHPC in terms of slump flow, compressive strength, tensile strength, flexural strength, and modulus of elasticity was evaluated. As well as water sorptivity and permeability, and chloride penetration of SUHPC were also evaluated. The results indicated that SUHPC could be prepared when replacing 50% of the OPC weight with (SLA 25% + RHA25%) with a compressive, tensile, and flexural strength of more than 155, 19, and 27 MPa, respectively. Moreover, substituting 50 wt% OPC with (RHA) reduced the water permeability and chloride penetration to 1.45 × 10−6 cm/s and 220 Coulombs, respectively.

Abd-Elrahman M.H., Agwa I.S., Elsakhawy Y., Rizk M.S.

This study investigates the utilisation of a combination of a few materials with various ratios, such as ferrosilicon (FS), recycled steel fibres (RSFs) resulting from waste tires and recycled granite (RG), to enhance the mechanical behaviour of ultra-high-strength concrete (UHSC). FS is a novel material that may be utilised as a partial replacement for the cement generated from the industrial waste product of FS alloy. The replacement ratios of FS used in this study are 10%, 20% and 30%. In addition to RSFs resulting from waste tires with ratios by volume of 0.5%, 1%, 1.5% and 2%, RG with replacement ratios of 25%, 50%, 75% and 100% from natural dolomite are used. The outcomes are represented in slump values, compressive strength, splitting tensile strength, flexural strength and modulus of elasticity. Microstructure analysis is also conducted to demonstrate the details of FS. Results reveal that the relatively better ratios to obtain high mechanical properties are 50% replacement of RG from natural dolomite and 20% replacement of FS from cement. The compressive strength of this mixture increases by about 11.11% over that of its reference mixture. The inclusion of RSFs obviates the brittle failure pattern of the tested cylinders, and a ductile failure occurs.

Abd-Elrahman M.H., Saad Agwa I., Mostafa S.A., Youssf O.

Cement production is classified as a highly contaminating process in recent decades, and numerous efforts have been accomplished to reduce cement used in construction for more sustainability. Cement complementary materials make an ecological impact on its manufacturing, in which the cement production cost can be reduced. In this investigation, peanut husk ash (PHA), as a newly abundant agro-industrial waste ash, was used as a substitution for ordinary Portland cement (OPC) in ultra-high-strength concrete (UHSC). PHA was heat-treated at various temperatures of 400, 500, 600, and 700 °C and utilized with substitution rates of 2.5%, 5.0%, and 7.5%. In addition, recycled granite was utilized as a coarse aggregate in UHSC. Thirteen mixes were prepared and tested to examine the fresh, mechanical, physical, and microstructure characteristics of the proposed UHSC. Concrete slump, compressive strength, indirect tensile strength, flexural strength, bond strength, modulus of elasticity, and water permeability were the measurements in this study. In addition, microstructure characteristics were obtained through X-ray diffraction analysis (XRD), thermo gravimetric analysis (TGA), and scanning electron microscope (SEM). The acquired outcomes revealed that utilizing 5% PHA as a partial substitution of OPC achieved high mechanical characteristics, and the optimal temperature for treating the peanut husk ash was 600 °C. The results of this experimental investigation can contribute well to illustrating the effect of utilizing PHA as a novel agricultural waste ash in UHSC to achieve significant financial benefits and a favorable ecological impact.

Amin M., Zeyad A.M., Tayeh B.A., Agwa I.S.

High-strength self-compacting concrete (HSSCC) is a special concrete that mixes self-compacting and high-strength properties. The production of HSSCC may require a high cement content, which increases the cost and limits production. This research focuses on producing HSSCC using glass powder (GP) to reduce the cement content and absorb glass waste. In this research, the experimental study was conducted on the degree of eleven experimental mixtures for SCC samples. Two types of glass waste powder (bottle glass powder and window glass powder) were added as a partial substitute for cement in proportions 10-50% by weight of cement. To evaluate the performance of GP, tests on workability, compressive strength, and transport characteristics (Chloride Permeability, Sorptivity Coefficient, and Water Permeability) were performed. The results showed that adding GP to concrete improved its fresh properties, which met the requirements of EFNARC specifications. The results also showed that adding GP decreased compressive strength with an increase in replacement rates. On the other hand, the transport properties improved, and the water and chloride permeability decreased with GP compared to the reference mixture. Keywords: High-strength self-compacting concrete, bottle glass powder, window glass powder, fresh properties, compressive strength, transport properties

Qin Z., Jin J., Liu L., Zhang Y., Du Y., Yang Y., Zuo S.

The reuse of soil-like material (SLM) obtained from landfill mining as engineering backfill materials contributes to sustainable waste management. In this paper, a new biomass fly ash-based binder (BB) containing biomass fly ash (BFA), carbide slag (CS), and phosphogypsum (PG) is designed to solidify the SLMs. The mechanical properties, permeability, microstructure, and physicochemical characteristics of the BB-solidified SLM are comprehensively characterized. The optimum proportion of ternary BBs consisting of 80% BFA, 15% CS, and 5% PG was determined through tests on paste samples. The different landfill depths of SLMs show significant variability in solidification/stabilization (S/S) effects due to their different physicochemical properties. The mechanical and permeability properties of BB-solidified SLM improve with the increasing BB content and the age of solidification. Microstructural and phase analyses indicated the formation of significant amounts of ettringite crystals and C-(A)-S-H gels were generated by the pozzolanic reaction, forming a stable and dense microstructure. The variations in pH and conductivity were correlated with the development of mechanical properties. Moreover, the organic matter content and leached heavy metal content of SLM2 and SLM3 after S/S treatment did not exceed the specified limits. This study can provide theoretical guidance for the resource utilization of the stabilized/solidified SLMs.

Zhao R., Wang M., Guan X.

Chloride ion attack is a major cause of concrete durability problems, and existing studies have rarely addressed the effects of damage zones. In this paper, an improved mesoscale model including five phases was constructed using the finite element software ABAQUS to study the diffusivity of chloride ions in cracked concrete. It was found that the damage zone is negligible when the crack width is less than 50 μm, while the width and depth of the damage zone are about 15 times the crack width and 15% of the crack depth when the crack is greater than 50 μm. The results show that the diffusion of chloride is greatly influenced by the crack width, while it is little-influenced by the crack shape. Low water–cement ratio and adequate hydration of the concrete are also key factors affecting chloride diffusion. In contrast, regular rounded aggregates have a positive effect on reducing chloride diffusion compared to irregularly shaped aggregates, and this effect becomes weaker with increasing service time. In addition, the protective layer can effectively prevent the diffusion of chloride in concrete. Therefore, when designing marine concrete, efforts should be made to ensure that the concrete has a low water–cement ratio, adequate hydration, less cracking and a protective layer.

Ahmad M.R., Das C.S., Khan M., Dai J.

Flue gas residues (FGR), a waste from incineration plant was utilized as an alternative alkaline activator to energy intensive and costly commercial activators. Fly ash (FA) and slag were used as precursors materials along with the FGR to produce low-carbon and cost-effective alkali-activated materials (AAMs). Reaction products and micromechanical properties were investigated by advanced microstructure analysis techniques. Results from the infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), scanning electron microscopy (SEM) and nanoindentation indicated that reaction products were comprised of N-A-S-H gel as a major reaction product along with the hybrid gel (C–N-A-S-H) and C-A-S-H gel. SEM-EDS and nanoindentation results showed that the formation of C-A-S-H gel was directly related to the content of FGR. The increase in volume of Ca-based reaction products (C–N-A-S-H and C-A-S-H) was associated with the activation of slag in presence of Na2SO4. Besides N-A-S-H gel, some new reaction products (zeolite, apatite and berlinite) were also observed from XRD analysis of pastes. The compressive strength of AAMs was in the range of 33.5–39.6 MPa and was in line with microstructure analysis results. Leaching concentrations of Ag, Ba, Cd, Cu and Zn heavy metals in FGR were 0.10, 0.40, 0.63, 0.26 and 1.65 mg/L respectively and below the regulatory limits and it was classified as a non-hazardous material.

Maglad A.M., Amin M., Zeyad A.M., Tayeh B.A., Agwa I.S.

Agricultural countries suffer from growth problems of agricultural waste ash (AWA). This research paper studies the use of AWA as a partial substitute for cement to produce ultra-high-strength concrete (UHSC). This paper also investigates the effect of using sugarcane bagasse ash (SBA) and corn stalk ash (CSA) on the properties of UHSC. Residues from the combustion process of agricultural wastes are utilized as a pozzolanic material inserted as a partial substitute for cement for UHSC production. The replacement rates of cement by the SBA were 10%, 20%, and 30% of the mass, whilst those of cement by the CSA were 2%, 4%, 6%, and 8% of the mass. The effects of SBA and CSA on workability, compressive strength, splitting tensile strength, flexural strength, and modulus of elasticity on UHSC properties were investigated. In addition, the effects of SBA and CSA on resistance to chloride ion penetration and water sorptivity and permeability in UHSC were investigated. The investigations showed impressive results. That is, producing UHSC with respective compressive and flexural strengths of more than 205 and 27 MPa is possible when 24% of cement mass replacement by AWA (SBA 20% + CSA 4%) is conducted at the test age of 28 days. The lowest permeability is achieved with 38% of cement mass replacement by AWA (SBA 30% + CSA 8%) of 140 coulombs and 0.95 (cm/sec) for chloride and water permeability, respectively.

Yuan J., Gan Y., Chen J., Tan S., Zhao J.

The influence of creep deformation of soft soil on engineering construction can’t be ignored. In order to deeply understand the macroscopic mechanical properties and the evolution mechanism of soft soil in microscope during consolidation creep, one-dimensional consolidation creep tests and SEM tests of Nansha soft soil were carried out in this paper. Then the image processing was performed by Image J software to obtain the consolidation creep characteristics, microscopic parameters of particles and pores under different loading pressures. The results of experiment and image processing show that 1) The creep process of Nansha soft soil is divided into the initial instantaneous deformation phase, the attenuation creep phase and the stable creep phase. The creep deformation increases with the consolidation creep stress during the three phases. 2) During the creep process, the distance between particles decreases and some particles are gradually broken, the quantity of particles and pores increases but the volume of them decreases. At the same time, the shape of particles and pores changes from nearly round and strip to nearly oval. 3) The consolidation creep stress determines the particles distance and the degree of fragmentation. And this trend is more obvious with the increase of the consolidation creep stress.

Zhang W., Kang S., Huang Y., Liu X.

Mostafa S.A., Tayeh B.A., Almeshal I.

Producing sustainable concrete using waste materials has a noticeable impact on the environment. From another aspect, understanding the effect of high temperature on concrete can help in reduce the environmental fire impact and lower rehabilitation costs. This study presents a systematic experimental investigation to produce sustainable ultra-high-performance basalt fibre self-compacting concrete (UHPBF-SCC) using agricultural waste materials including nano sugar cane bagasse, nano cotton stalk ash and nano rice straw ash as cement replacement. The three dosages of nanoparticles are mechanically produced after heat treatment at 700˚C. The performance of the three dosages of nanoparticles (partially replacing 1%–5% of cement) was investigated in the presence of basalt fibre. This study also examines the effect of elevated temperatures of 300˚C and 600˚C on the behaviour of UHPBF-SCC. The physical properties, including passing ability, flowability and segregation resistance, were studied. Compressive strength, strength loss at elevated temperature, mass loss, ultrasonic pulse velocity, splitting, and flexure strength were also investigated. Scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDX) analysis were conducted to show the microstructure of the mixes. Mechanical characteristics are significantly increased in the presence of nanoparticles, more than 18% in compressive, 32% in tensile strength and 28% in flexure strength compared with the reference mix. SEM analysis showed compacted sections with high bonded matrix and high ITZ at normal conditions, but microcrack propagation appeared at 300˚C and 600˚C due to ettringite decomposition and evaporation of capillary and adsorbed water. EDX analysis showed high Ca/Si with the addition of nanomaterials.

Kumar A., Sen S., Sinha S.

In the current study, the effect of the inclusion of waste plastic in different quantities (0–10%) on the compressive strength of fly ash reinforced concrete is explored. Compressive strength decreases with increasing plastic waste due to its inert, hydrophobic nature and poor bonding within the concrete matrix, while 10% fly ash improves strength slightly through pozzolanic reactions that densify the matrix and reduce voids. Support vector machine (SVM) was explored as a potential machine learning technique for accurately predicting and modeling the compressive strength of concrete. Predictive models were developed using SVM-radial basis function (RBF), SVM-linear, SVM-power and linear regression. The models were analyzed using performance metrics such as mean absolute error (MAE), mean squared error (MSE), root mean squared error (RMSE), mean squared logarithmic error (MSLE), root mean squared logarithmic error (RMSLE), coefficient of determination (R2), mean absolute percentage error (MAPE), Willmott's index of agreement, Mielke and Berry index, and Legates and McCabe's index. Taylors diagram was also used to analyze the models. SVM-RBF model outperformed all other models with an R2 value of 0.969 and 0.771 in training and testing respectively. Sensitivity analysis revealed that % plastic waste is the most influential parameter in predicting the compressive strength of concrete with a score of 59.04%.

Helmy F.M., El-Gamal S.M., Ramadan M., Selim F.A.

AbstractThis research aims to produce green cement, as an alternative to traditional cement, with outstanding performance. Five alkali-activated cement pastes were fabricated based on NaOH-activation of slag (GGBFS), bypass (B), and/or silica fume (S). Codes of five pastes are C, C-20B, C-30B, C-10B10S, and C-20B10S, as C is the control paste containing 100% slag. The compressive strength of the fabricated pastes was measured at different curing regimes: Conventional curing for 3 months and autoclave curing at 4 bar/153◦C, 7 bar/178◦C, and 10 bar/198◦C for 4 h. XRD, TGA/DTG, SEM/EDX, and BET/BJH techniques were utilized to clarify the phase development, morphological and texture features of the formed alkali-activated composite pastes. Besides, the removal capacity of some pastes for methylene blue and indigo-carmine dyes from aqueous media was evaluated. The results confirmed that C and C10B10S (80%GGBFS + 10%B + 10%S) pastes have significant mechanical properties and distinctive meso-porosity that can remove both anionic and cationic dyes.