Alternative Construction Materials Research Articles

Brick: sustainability through policy

ABSTRACT The brick has become a remarkable political symbol with the laying of the silver brick in Ayodhya, India, recently. A tangible material in this whole exercise; the humble, everyday ‘brick’became the symbol of nationalism. While this building material holds such a shiny political campaign in the form of a silver brick today, the on-ground situation of brick kilns is rather grim, which exploits labour and deteriorates the environment. To change this scenario there needs to be change in policy that includes an array of solutions for brick making, including Stabilised Compressed Earth Blocks, adobe etc. To keep a check on these ecological imbalances, firstly at policy level intervention, the government should initiate decentralised, smaller and regional production systems instead of global chains. Secondly, alternate construction materials should be made mainstream, and an array of innovative local technologies should be incorporated instead of propagating one chief solution, universally, for brick production. Absence of environmental emission policies and regulatory enforcement leave no incentive for brick manufacturers to adopt less polluting industries and the added lack of policies that address the demand-side issues, even though appropriate technologies may be present, make it worse. There is an urgent need to revamp the brick industry of the world, especially in the emerging economies where the next decades will see exponential growth.

Sustainable lightweight self-compacting concrete using oil palm shell and fly ash

This research investigated fresh and hardened properties of lightweight self-compacting concrete (LWSCC) incorporated with oil palm shell (OPS) and fly ash (FA). Fresh concrete properties including passing ability, filling ability and segregation resistance were assessed. The properties fulfilled EFNARC guidelines. Incorporation of FA improved fresh properties, particularly filling ability, with the slump flow value increased from 665 mm to 730 mm. As for hardened properties, OPS-aggregate based LWSCC mixes achieved compressive strength of range 18–38 MPa at 28-day age while the splitting tensile strength was in the range of 1.6 to 2.8 MPa. SEM analyses showed good bonding in the interfacial transition zones (ITZ). Micro-pores of OPS were filled by cement hydration products and thus ITZ was enhanced. LWSCC incorporated with OPS, a renewable resource from agricultural waste, and with partial FA replacement, is potentially a sustainable alternative construction material.

The Potential of Recycled Aggregates and Coconut Fiber in the Production of Concrete

The high cost of conventional construction materials has led researchers into the search for alternative construction materials that are sustainable and eco-friendly. This study investigates the effect of crushed sandscrete block as recycled fine aggregate (RFA) and crushed abandoned cubes as recycled coarse aggregate (RCA) with constant percentage of coconut fibre (CF) on the properties of the concrete. The normal aggregate concrete (NAC) containing normal aggregate (NA) without the addition of CF was first produced and tested. The second stage involved production of concrete comprising constant percentage of CF with 25%, 50%, 75% and 100% fine and coarse aggregate replacement by weight with RFA and RCA. Properties of fresh and hardened concrete for all specimen types with standard procedure to obtain an optimum mix design was determined. The results obtained from the study shows that the workability of all the replacements were found to be lower than that of the normal aggregate concrete (NAC). Compressive and splitting tensile strength test showed that at optimum replacement levels of 25% RCA and 25% RFA concrete have better strength performance than NAC. The study established that RCA and RFA is capable of partially replacing NA in concrete production in ternary form. The optimum percentage replacement of RCA, RFA and CF should be adhered to for effective performance.

Eggshell Produced Limes: Innovative Materials for Soil Stabilization

AbstractThe search for innovative solutions that reduce the need for exploitation of natural resources and make use of residues to produce alternative construction materials is a necessity. Eggshel...

Geopolymer Synthesis Using Metakaolin and High Calcium Fly Ash as Binary System Geopolymer

Conventional cement production process emits tons of carbon dioxide gas which is one of the greenhouse gases that influence the environment across the world. Discovering the alternative construction material with the eco-friendly process and the performance similar to or greater than ordinary Portland cement has been attractive to find out. This research presented green construction materials or so-called geopolymers from metakaolin substituted by high calcium fly ash by 20, 40, 60, 80 and 100 wt%. Some researches reported that geopolymer produced from metakaolin and fly ash with alkali solution gave a great result, but usually, they used fly ash containing very low calcium component. Compressive strength at 3, 7 and 28 curing days and flowability were conducted. The compressive strength of geopolymers blended with high calcium fly ash was still developed as the curing day increased and revealed the highest at 28 days especially on MK40 (high calcium fly ash 60 wt%). Geopolymer pastes prepared with a higher amount of high calcium fly ash exhibited less viscous. It was proved that the high amount of high calcium fly ash could be applied and gave extraordinary compressive strength. Furthermore, X-ray diffraction and X-ray fluorescence were used to investigate chemical properties as well as microstructure by a scanning electron microscope. For phase analysis, the existence of oxides of calcium and sulfur in high calcium fly ash resulted in the formation of thenardite, calcite, portlandite and C-S-H phase associating with geopolymeric phase. Therefore, this research proposed the opportunity for geopolymer production by using abundant high calcium fly ash to raise the value of the industrial waste products and green alternative construction material compared with OPC.

Rendimiento de compuestos de yeso que incorporan partículas de neumáticos de goma

Gypsum is the oldest synthetic construction material that is known, however it is a material about which there is little knowledge at the level of research, and in this work its study took place by making composites with the incorporation of rubber tires, aiming to obtain an alternative construction material. Thus, the objective was to investigate gypsum-based composites, with a mass incorporation of 5, 10, and 15% of two grades of vulcanized rubber residue from tire retreading processes. The granulometries are referred to as thin (sieve pass-through #0.60 mm) and thick (sieve pass-through #1.19 mm). The composites were investigated in terms of consistency (mini-slump), mass density, water absorption, surface hardness, flexural strength, compressive strength, scanning electron microscopy (SEM), and thermal behavior. The results revealed that rubber incorporation can be attractive in gypsum composites: in which the consistency decreased with the increase of the rubber content and the thick rubber granulometry favored the workability of the composites; the mass density was reduced, mainly with thin granulometry, as the rubber content in the composites increased; the water absorption showed that the high levels of rubber favor the penetration of water in the composites, regardless of the granulometry; the surface hardness showed reduced impact energy provided by the composite with 10% thin rubber; in both flexural strength and compression, the composite with 5% thin rubber showed a similar result to the control composite, while composites with 15% rubber suffered a gradual drop of up to 60 and 40%, respectively; with SEM it was observed that the thin rubber composites had smaller pores, in addition to more effective adhesion between the rubber particles; finally the rubber helps to reduce the thermal amplitudes during the day, mainly with the increase of the particle size and the rubber content .

Manuscript title: Development of strength prediction models for fly ash based geopolymer concrete

Geopolymer concrete has progressively gained acceptance as one of the best alternative construction materials in civil and infrastructural engineering applications. The geopolymer binders have excellent mechanical properties and commercial potential, with lower environmental impact compared to ordinary Portland cement. In the past, most studies have focused on mixtures, properties, mixing and curing process, and micro-structure, etc., of the geopolymer binder. However, studies on structural member design using fly ash geopolymer concrete are still limited and do not have comprehensive coverage. Furthermore, some design parameters are rarely available, and this has slowed down the development of applications. The objective of this study was to evaluate and establish strength parameters of fly ash geopolymer concrete under flexural, shear and torsion loadings, utilizing prior experimental data and those from various standard design codes such as ACI, AS3600, CSA, and CIB-FIP. Models of modulus of rupture, elastic modulus, torsional strength, and flexural beam shear were developed in terms of compressive strength. In our experimental study, three different experimental sets were performed: 1) uniaxial compression and flexural beam test to evaluate modulus of rupture, 2) uniaxial compression and torsion test to determine cracking torsional strength, and 3) beam test (with shear span to effective depth ratio (a/d) ≈ 2) and uniaxial compression test to characterize shear strength. By using experimental data of the current and prior studies, the modulus of rupture model was developed in terms of an exponential function for the geopolymer concrete compressive strength, with acceptable accuracy. The modulus of elasticity in a power function was more accurate with 85% R2 for a board range of compressive strengths. The proposed cracking torsional strength model, based on thin-wall theory, was established with the critical stress 0.47√f'c. The proposed shear strength estimate having similar form as the original ACI equation is reasonably conservative and facilitates the practical use of geopolymer concrete in structural design.Finally, the interaction surface for combined loads, such as bending, shear and torsion was demonstrated for the quarter-parabola bending –shear and – torsion, and for the quarter - circle torsion and shear interactions, with the critical stresses: (fb = 0.815f′c), (fs = 0.11f′c) and (ft = 0.30f′c), respectively.

Technical Suitability Assessment of Autoclaved Aerated Concrete Block as Alternative Building wall Construction Material; A Case of Nepal

Technical Suitability Assessment of Autoclaved Aerated Concrete Block as Alternative Building wall Construction Material; A Case of Nepal

Prediction and model development for fatigue performance of pervious concrete made with over burnt brick aggregate

The inadequacy of regular stone aggregate in North East India, has motivated the developers to search for an alternate construction material and prime subject of the present study is to use waste crushed bricks as a coarse aggregate in pervious concrete pavement. Pervious concrete, due to its inclusive beneficial aspects has become an embryonic solution to fight against the current hydrological and environmental threats. A number of research have been carried out to characterize the pervious concrete, however, there is a lack of study related to the fatigue performance of pervious concrete pavement. As the pavements are often subjected to fatigue loading, the present study mainly focuses on the response of pervious concrete pavement under the action of fatigue loading. Laboratory tests are performed on beam specimens under various stress levels and loading frequencies. Different types of aggregate gradations are also used to account the size effect of the coarse aggregate. The S–N curves for fatigue life is generated to obtain the relationship between the stress level and fatigue life and it is observed that the S–N curve follows a power law, irrespective of loading frequencies. The survival percentage of porous specimens are checked through non-parametric Kaplan–Meir survival analysis and the distributions of the fatigue data are checked through lognormal and 3-parameter Weibull distributions. Further, a modified fatigue model is developed for idealising the fatigue life of pervious concrete pavement made with over burnt brick aggregate and compared with the existing fatigue models.

An evaluation of the performance of hot mix asphalt containing calcium carbide residue as a filler

The reduction of both environmental problems and construction costs has motivated the asphalt pavement industry to increasingly use waste materials as alternative raw materials in road pavements construction. This investigation aims to explore the potential of waste calcium carbide residue (CCR) for use as a filler in hot mix asphalt (HMA), by substituting traditional limestone filler in various proportions. Asphalt mixes were prepared using different CCR ratios (0%, 3% and 6%) by aggregate dry weight, their strength, properties and performance evaluated against the indirect tensile stiffness modulus, rutting, crack initiation, crack propagation and moisture damage. The results show that stiffness modulus and resistance to permanent deformation and cracks have been enhanced due to the addition of CCR. HMA modified with CCR was also found to be less sensitive to water damage than traditional HMA with limestone filler. A toxicity characteristic leaching procedure (TCLP) test revealed that the CCR used in the production of HMA has no environmental impact. Therefore, based on this study, CCR can be considered as a plausible alternative to conventional filler in HMA, the implication being that large amounts of waste carbide lime can be removed from landfill, thereby significantly reducing environmental damage.

English

English

Mechanical strength characteristics of fiber-reinforced pond ash for pavement application

The pavement construction sector throughout the world is facing a major challenge of non-availability of suitable construction materials. On the other side, many waste/sub-products are being generated from manufacturing/production units causing environmental pollution. One of such waste materials is pond ash produced from thermal electric power plants, which can be utilized as an alternative construction material in place of traditional materials. In this context, an attempt was made on fiber-reinforced pond ash as subbase layer of flexible pavements to understand its engineering behavior by conducting static (California bearing ratio, CBR) and dynamic (repeated load triaxial, RLT) tests. Randomly distributed polypropylene fibers of various proportions were used in pond ash as reinforcement inclusions. The test results were analyzed to address the influence of fiber on conventional parameters of pond ash such as CBR, resilient modulus (MR), and permanent strain (ϵp). Also, the influence of confining (σc) and deviatoric stress (σd) levels on MR as well as ϵp with load cycles have been investigated for both unreinforced and reinforced pond ash. The results obtained have shown that the inclusion of fiber improves the CBR, MR and ϵp characteristics of the pond ash. With an increase in stress levels (σc and σd), the MR of reinforced pond ash increased compared to non-reinforced ash. Irrespective of the fiber content in pond ash, permanent strain values were increased with an increase in the number of loading cycles and cyclic deviatoric stresses. However, with the introduction of fiber, the rate of strain development in pond ash was reduced significantly. Furthermore, the experimentally obtained MR and ϵp values were validated against existing models established by previous researchers. From the above findings, it can be concluded that fiber-reinforced pond ash can be used effectively in pavement layer applications.

Effectiveness of using rubber waste as aggregates for improving thermal performance of plaster-based composites

In this paper, rubber waste is added to plaster-based composite to produce an alternative construction material. The main goal of this study is to investigate the effectiveness of using shredded rubber waste as aggregates in plaster mortar for improving its insulating aspect potential. This composite is obtained by mixing dune sand, plaster, rubber particles, and water. The rubber aggregates are incorporated in mixes as a partial replacement by volume of some parts of sand. Unit weight, capillary absorption of water, mechanical, and thermal-related properties are evaluated and compared according to the percentage of rubber in the mix. The results obtained showed that the addition of rubber will modify the properties of the mortar. Even though the mechanical strength is decreased with the increase of rubber content, it should be mentioned that rubber particles could significantly reduce the weight the material, decrease the rate of water absorption, and improve the insulation aspect of the composite. It can be noted that, below 50% of rubber, modeling by auto-coherent homogenization confirms the experimental results of thermal conductivity. Finally, it should be noted that recycling of rubber waste can produce an alternative eco-friendly material.

Development of sustainable bricks using ash from co-fired sawdust and coal

Ash obtained from co-combustion of sawdust and coal was studied to determine its potential to be used as an alternative construction material. The ash was subjected to chemical, physical and mineralogical characterisation. It was then mixed with cement and sand in various proportions and made into bricks. These were tested for compressive strength, density, water absorption, efflorescence, durability (chloride and sulfate) and thermal conductivity. The equivalent energy required during production of the bricks was compared with commercially available fly-ash (FA) and burnt-clay bricks. The produced bricks complied with Indian standards. A comparative analysis showed that the bricks were 26% and 15% lighter and 50% and 58% less thermally conductive than FA and burnt-coal bricks, respectively. Also, the embodied energy was 19% and 48% less than that of FA bricks and burnt-coal bricks, respectively. The overall study suggested that the sawdust–coal ash bricks are energy efficient, lighter in weight and better in thermal performance as well as providing a sustainable solution to meet the increasing demand for construction materials.

Cost Comparison for the Installation of Steel Frames vs Wooden Frames on a Traditional Wooden Fishing Boat in South Sulawesi

Traditional wooden fishing boats are still being produced by most of the traditional wooden shipyards in Indonesia specifically in the area of South Sulawesi. Nevertheless, the traditional wooden boat craftsman facing the difficulty of wooden log supply as the main wooden boat material especially for wooden frame construction despite the increasing demand for wooden material for the boat construction. The difficulty to acquire the specific wooden for wooden frame caused by the specific requirements of each wooden frame. They must be in the specific shape according to the specific curvature of each transversal boat section along the boat length. Hence, for the sustainability of wooden boat construction process, alternative material is needed for replacing the certain wooden boat construction component, especially for wooden frames. Fortunately, research relating to the use of alternative material for wooden boat construction have been conducted. The focus of the research is on the use of steel frame to replace the wooden frame on the wooden boat construction. This paper discusses the cost comparison for the fabrication and installation process as well as the material cost of the steel frame to the wooden boat construction with wooden frame to the wooden boat construction. The result shows that the cost for fabricating and installing steel frame is 13% higher to compare to the wooden frame. However, if the total wooden boat construction cost is being considered, the total difference is only 3%.

Experimental investigation of fiber reinforced concrete using septage ash

In this experimental investigation, the concrete has replaced with septage ash in place of cement and banana fiber is added as a percentage of the weight of cement. Concrete is one of the materials which use a maximum number of non-renewable resources. Due to the high demand for non-renewable resources in the construction industry, recent investigations are carried out to find alternative construction materials which are eco-friendly and cause some impact in reducing pollution in the environment. Septage ash or septic tank sludge is the by-product from the faucal sludge sewage treatment plant of household septic tanks. Banana fiber is the natural fiber which is obtained from the stem of the banana tree, banana fiber is mainly used in the textile industry, but a huge quantity of fiber which can’t be used in the textile manufacturing is as waste. So, in this experimental investigation authors have used these two materials to find the optimum percentage that can be replaced in concrete. In this research septage ash is put back by 10%, 20%, 30%, and 40% instead of cement without and with banana fiber added 1% of the weight of cement. Compressive, tensile along with flexural strength test is conducted for 7days and 28 days and results are compared to finding the optimum percentage of septage ash with banana fiber that can be replaced instead of cement.

Accelerated Carbonation of Recycled Aggregates Using the Pressurized Supercritical Carbon Dioxide Sparging Process

The carbonation of recycled aggregate was accelerated by sparging with supercritical carbon dioxide (scCO2) to reduce the amount of time needed for carbonation, which is necessary for the pH neutralization of recycled aggregate. To accelerate the carbonation process, pressurized scCO2 was sparged into two different types of recycled aggregates immersed in water for 1 h, followed by standstill for 2 h (in total, a 3 h treatment process). The reduction of the pH of the treated aggregates due to carbonation was investigated using batch extraction experiments. A continuous column extraction experiment for the scCO2-sparged recycled aggregate was also performed to identify the effect of pH reduction under the condition of non-equilibrium reaction. From XRD, SEM/EDS, and TG/DTA analyses, much of the portlandite in the recycled aggregates was consumed. In its place, calcite was created as a secondary mineral during only 3 h of treatment (1 h scCO2 sparging and 2 h stationing), indicating satisfactory carbonation of the aggregate. The results of the batch extraction experiments for both of the two recycled aggregate types also showed that the average pH of scCO2-sparged aggregate decreased from 12.0 to <9.8 (the tolerance limit for recycling). The pH of the eluent from the column packed with the scCO2-sparged aggregate also remained as <9.8, suggesting that a 1 h scCO2 sparging process is sufficient to carbonate waste concrete aggregate and to create an alternative construction material resource.

Overcoming the concrete conquest of aquatic ecosystems

In reflecting on the human domination of our planet in the Anthropocene, some have argued that concrete is among the most destructive materials created by humans. Here we explore this idea, specifically in the context of what we consider “the concrete conquest of aquatic ecosystems.” The ubiquitous use of concrete in transportation and building infrastructure has contributed to alterations in freshwater and coastal marine systems. Yet, in some cases, there are no appropriate alternative building materials such that concrete itself is confounded by its application. For example, as the foundation for most dams, concrete fragments rivers and channelizes streams, often creating unnatural systems, yet dams are necessary for hydropower generation and flood control with few alternative materials for construction. In riparian and coastal environments, concrete harbours and inland canal systems are often used to address erosion or reclaim areas for human development. Even when removed (e.g., dam removal, naturalization of shorelines), concrete dust is a major aquatic pollutant. Instances do exist, however, where concrete has been used to benefit aquatic ecosystems – such as the installation of fish passage facilities at barriers or the development of fish-friendly culverts – though even then, there is a movement towards nature-like fishways that avoid the use of harmful materials like concrete. There are also opportunities to achieve conservation gains in the development of seawalls that include more natural and complex features to benefit biota and allow for essential biogeochemical processes to occur in aquatic environments. There have been several innovations in recent years that increase the permeability of concrete, however these have limited application in an aquatic context (e.g., not relevant to dam construction or erosion control but may be relevant in stormwater management systems). We provide a brief overview of the history of concrete, discuss some of the direct and indirect effects of concrete on aquatic ecosystems, and encourage planners, engineers, developers, and regulators to work collaboratively to explore alternatives to concrete which benefit aquatic ecosystems and the services they offer. The status quo of concrete being the default construction material is failing aquatic ecosystems, so we recommend that efforts are made to explore alternative materials and if concrete must be used, to increase structural complexity to benefit biodiversity.

Sulfate attack and embedded steel corrosion resistances of volcanic-aggregate concrete with fly ash and silica fume

Construction materials are increasingly on high demand in the developing world. The construction industry has a challenge of discovering, new alternative construction materials to conventional materials which are locally available materials in environmentally friendly manner. The experimental tests are conducted on volcanic concrete system to analyze its properties especially corrosion resistance potential for its applicability in construction. The major aim is to investigate its suitability and corrosion resistance potential especially when used in construction of structures with embedded steel. The test results of the material show that volcanic concrete system with 30% fly ash and 10% silica fume cementing materials is an alternative green construction material. Permeability properties are reduced by 8% and 24% with 30% fly ash and 10% silica fume respectively. Tests also indicate that Compressive strength, Corrosion potential and polarization resistance in volcanic concrete system with supplementing cement materials has more potential to resist sulfate attack when compared with conventional volcanic concrete systems. The supplementary cementing materials (SCM) reduce the pore system and hence decrease the ingress of corrosive ions an water in concrete. Corrosive ions, moisture and air would initiate corrosion to the embedded steel in concrete leading to reduced service life such structures.
 Key word: Supplementary Cementing Materials, Sulfate attack, volcanic concrete system, Granite powder, river sand, Corrosion of embedded steel

Alkali-activated concretes based on fly ash and blast furnace slag: Compressive strength, water absorption and chloride permeability

Concretes based on alkaliactivated binders have attracted considerable attention as new alternative construction materials, which can substitute Portland Cement (OPC) in several applications. These binders are obtained through the chemical reaction between an alkaline activator and reactive aluminosilicate materials, also named precursors. Commonly used precursors are fly ash (FA), blast furnace slag (GBFS), and metakaolin. The present study evaluated properties such as compressive strength, rate of water absorption (sorptivity), and chloride permeability in two types of alkaliactivated concretes (AAC): FA/GBFS 80/20 and GBFS/OPC 80/20. OPC and GBFS/OPC* concretes without alkaliactivation were used as reference materials. The highest compressive strength was observed in the FA/GBFS concrete, which reported 26,1% greater strength compared to OPC concrete after 28 days of curing. The compressive strength of alkaliactivated FA/GBFS 80/20 and GBFS/OPC 80/20 was 61 MPa and 42 MPa at 360 days of curing, respectively. These AAC showed low permeability to the chloride ion and a reduced water absorption. It is concluded that these materials have suitable properties for various applications in the construction sector.