Use Of Construction Waste Research Articles

Construction waste as a filler of denitrification biofilter for nitrate utilization from wastewater: Characteristics, performance, microbial community and soilless culture

Construction waste (CW) is produced in large quantities, resulting in severe land occupation and resource depletion. This study utilized CW as fillers to construct a denitrification biofilter (DNBF-CW) for treating secondary effluent from wastewater plants. Performance and mechanism were analyzed by water quality, biomass and its distribution, physicochemical characteristics, microbial community structure, extracellular polymeric substances and protein secondary structure analysis. Results indicated that DNBF-CW achieve NO3−-N and chemical oxygen demand (COD) removal efficiencies (RE) of 97 % and 70 %. The β-sheet of DNBF-CW increased from 47 % to 58 %, accompanied by decrease in random curls from 22 % to 0. Post-use CW showed potential as soilless cultivation substrates, boosting germination rates by 42 ± 7 %. Mechanism investigations elucidated that ZX3 improved efficiency by modulating microbial community composition, with Pseudomonas reaching 37 %. This study shows the multiple use of construction waste, which presents a novel, efficient, and eco-friendly solution for water treatment.

Pengaruh Penggunaan Limbah Beton Sebagai (Agregat Halus) Terhadap Uji Kuat Tekan Paving Block

In Indonesia, the use of construction waste is usually not utilized properly most are simply dumped in open fields, and some are used as backfill material. The availability of such materials is vast. The purpose of this research is to determine the compressive strength value of paving blocks that utilize concrete waste with variations in the use of concrete waste, namely: 0%, 10%, 20, 30%, and the value of water absorption in paving blocks that utilize concrete waste with variations in the use of concrete waste, namely: 0%, 10%, 20, 30%. The test results showed that at 28 days of soaking, the compressive strength of normal paving blocks was 16.15 MPa, at 10% substitution of concrete waste for stone ash was 29.17 MPa, at 20% substitution of concrete waste to stone ash amounted to 39.32 MPa, and at 30% substitution of concrete waste to stone ash amounted to 22.66 MPa. From the results of the absorption test, it was found that the absorption value of normal paving blocks was 3.88%, at 10% substitution of concrete waste was 2.30%, at 20% substitution of concrete waste for stone ash was 1.89%, and at 30% substitution of concrete waste for stone ash was 2.80%.

Influence of recycled aggregates and silica fume on the performance of pervious concrete

A large amount of waste is produced daily, across cities worldwide. To ensure that this waste is not discarded incorrectly and does not pollute the environment or occupy areas for other purposes, we must find ways to reuse it. This work proposes the evaluation of pervious concrete with construction and demolition waste from a recycling plant. It is a proposal that unites the use of construction waste with the positive contribution of pervious concrete that allows rainwater to infiltrate it. To determine the appropriate mix for high-strength pervious concretes, pervious concrete with a superplasticizer additive, 10 % silica fume, natural aggregate, and replacing natural aggregates with 40 %, 50 %, and 60 % recycled aggregates were analyzed. The following tests were performed: absorption, void ratio, permeability, compressive strength, flexural tensile strength, thermal analysis, X-ray diffraction, and scanning electron microscopy. The performance of the material was evaluated by building an experimental track with pervious concrete made of natural aggregates and replacing natural aggregates with 40 % and 60 % recycled aggregates. With an increase in natural aggregates from 40 % to 60 % in pervious concrete, a reduction in the compressive strength was observed compared to the control. Pervious concrete with 40 % recycled aggregates presented the best results for the properties analyzed. Further, all samples presented values higher than those established in the ABNT NBR 16416/2015 standard for use in pervious concrete in pedestrian traffic areas.

Mathematical Modeling of Technological Processes of Concreting Monolithic Structures From Fine-Grained Mixtures

Introduction. The introduction of innovative technologies and materials in the construction industry is constrained by a number of reasons associated with insufficient knowledge of technological processes and the increased cost of highly efficient innovative materials. Therefore, studies in the field of monolithic concrete technology, reflecting the features of concreting structures from self-compacting mixtures and aimed at reducing their cost due to the use of construction waste, are relevant. The purpose of this work is experimental and statistical modeling of rheological characteristics of finegrained self-compacting concrete mixtures and physical and mechanical properties of concretes depending on the influence of two recipe factors — consumption of superplastifying additive and particle size distribution of aggregate including construction wastes.Materials and Methods. For the preparation of fine-grained self-compacting concrete mixtures, portlandcement CEM 0 52,5N, natural quartz sand and crushed concrete sand of a mixture of three fractions of 0.63–5.0 mm and a chemical additive - a superplasticizer based on polycarboxylate esters Polyplast PK were used. Process characteristics of fine-grained self-compacting mixtures (workability, viscosity, fluidity) were determined by standard methods. The shear limits of the mixtures were set by means of an instrument comprising a cylinder with a nozzle and a glass base with circumferential marking. Modeling of rheological and physical-mechanical properties of fine-grained self-compacting concretes was carried out using a two-factor simplex-summed plan on a hexagon inscribed in a circle, which is one of the most convenient for solving technological problems of construction materials science.Results. Experimental-statistical models of rheological characteristics of fine-grained self-compacting mixtures and strength properties of concrete were obtained, adequately describing experimental data.Discussion and Conclusion. The use of mathematical planning methods of the experiment made it possible to comprehensively assess the influence of the two most significant recipe factors on the technological processes of concreting monolithic reinforced concrete structures from fine-grained self-compacting mixtures using aggregate from construction waste. It was established that optimal content of grains from crushed concrete in natural sand is 30–35 %, and dosage of superplasticizer Polyplast PK is 1.2–1.25 % of binder weight.

Investigation of the pore structure performance of dune sand mortar with ceramic waste

The use of construction waste in creating concrete and mortar is an important process that not only offers economic benefits but also helps protect the environment by reducing waste in rural and urban areas. This experimental study aims to investigate the effect of adding crushed ceramic waste (CCW) and crushed brick waste (CBW) on the bulk density, workability, compressive and flexural strengths, water absorption and microstructural properties of dune sand mortar. To determine changes in porosity, the study uses the mercury intrusion porosimetry technique to measure porosity and pore size distribution. Scanning electron microscopy and energy-dispersive X-ray spectroscopy analyses are conducted to examine the microstructure and size of the voids using an electron microscope, and photographs of voids in the mortar matrix are taken. By replacing 15% of the sand with CCW and CBW, the compactness and mechanical strength of the dune sand mortar are enhanced, increasing the dynamic modulus of elasticity by around 29 and 26%, respectively. This is due to the pozzolanic activity of these residues, which mainly occur in the form of medium and small capillaries in all the mortars studied, reducing the diameter of the pores.

Economic benefit analysis of the carbon potential of construction waste resource management based on a simulation of carbon trading policy.

The need for safer and cleaner environments for all humankind remains a topical issue that cannot be overemphasized. To provide an updated perspective, this study analyzes the carbon potential of construction waste resource management based on carbon trading policy. In this study, the system dynamics principle was used to establish a carbon potential model of construction and demolition waste (C&DW) resource treatment by taking the regeneration project of Xiancun Village as an example. The results showed that the use of construction waste for recycling and resource treatment can generate enormous opportunities to reduce carbon emission. The implementation of the carbon trading policy can create significant benefits in terms of reducing carbon emission, while the total reduction of carbon emission in the baseline scenario can reach 100.66% when compared to the scenario without a carbon trading policy. Moreover, the findings shows that the combination of the carbon trading policy of "carbon price + free allowance ratio" can improve the return on investment of resource utilization companies and the carbon reduction benefits of the combined policy are greater than those of the single policy, but only if the level of the carbon price or free allowance ratio in the combined policy is accepted by the carbon trading subjects. The results of this research contribute to the theory of construction waste resourceization management, provide the theoretical basis for government departments to introduce carbon reduction policies for construction waste resourceization, and provide guidance for the management of companies' carbon reduction.

The Use of Construction Waste to Remediate a Thermally Active Spoil Heap

This article presents the results of experimental research on the possible use of construction and demolition waste (CDW) to improve the properties of unburnt tailings originating from the thermally active spoil heap in Heřmanice (Ostrava, Czech Republic). Mining activity anywhere in the world generally entails a lot of negative impacts on the environment, which are of a long-term nature. One of the most pressing challenges in the remediation of the consequences of mining activity is the thermal activity of spoil heaps associated with the high acidity of the tailings. Active acidity (pH/H2O), exchangeable acidity (pH/CaCl2), hydrolytic acidity (Ha), and elemental composition of tailings and CDW have been monitored. Based on an acidity study, it has been proven that compared to burnt tailings (pH/H2O = 8.4, pH/CaCl2 = 8.9 and Ha = 1.4 mmol kg−1), unburnt tailings show acidic properties (pH/H2O = 3.7, pH/CaCl2 = 3.6 and Ha = 205 mmol kg−1). The bioavailability of two selected potentially toxic elements (PTEs), namely Al and Fe, was examined based on the elemental composition. BCR sequential extraction analysis was used to determine their bioavailability. It has been proven that mixing CDW with tailings has a positive effect on the pH value, which has a positive effect on the further development of the entire site. The increase in the pH value is provably dependent on the amount of construction waste added, so it can be said that the increasing amount of construction waste will result in improved parameters of the burnt tailings. The results of the BCR analysis show that aluminum from the tailings will be released both from the reducible and oxidisable fractions, where it will be mainly bound to sulphides. The relatively high concentration of Fe in the oxidisable fraction (2002 mg Fe kg−1) suggests that Fe is bound to sulphides in the tailings, and it is due to the high residual pyrite and sulphide content in the dumped material, as expected. This work has found no limits where CDW no longer positively affects the acidity of unburnt tailings. For practical application, however, it is important that the mixture of CDW and tailings is properly mixed and then used for remediation.

Nano-SiO2 Recycled Concrete Anti-Sulfate Performance and Damage Mechanism Research

The use of construction waste for concrete is an effective way to reduce the environmental burden while improving the sustainability of construction materials. Nano-SiO2 (NS) has excellent volcanic ash activity, which can effectively improve the strength of concrete. In this study, the synergistic effects of NS and 30% recycled concrete aggregate (RCA) on the mass loss, compressive strength, ultrasonic sound velocity values and microstructure of RAC after 25, 50, 75 and 100 repetitions of a dry–wet cycle (DWC) of sulfuric acid were investigated. The results show that NS has a significant role in improving RAC performance. The RAC specimens showed the lowest mass loss rate, the highest compressive strength, the lowest ultrasonic velocity value and the best resistance to sulfate erosion when the NS doping was 4%. Meanwhile, under CT and SEM, RAC with NS has lower porosity and higher hydration, which can effectively inhibit the crack generation and has stable volume growth within 0–50 repetitions of DWC. In addition, the addition of NS improves not only the microstructure of the substrate but also the interfacial transition zone (ITZ). When 4% NS was added, the porosity was the lowest and the durability improvement was the best performance. This study not only improves the production performance of RAC but also provides a strong reference for the integrated application of nanomaterials in concrete.

Simulação numérica de ruptura por punção em lajes de concreto com agregado reciclado com reforço de fibra de aço

Abstract The use of construction waste as aggregate in the production of concrete is becoming a more frequent alternative due to the advantages associated with the sustainability aspect. Results obtained in experimental tests with recycled aggregate concrete suggest that mechanical properties such as elastic modulus, compressive, tensile and flexural strength tend to reduce with partial or total replacement of natural aggregate by recycled one. On the other hand, the use of steel fiber reinforcement can minimize the reduction of these properties, since the fibers tend to improve the material strength and ductility. This work proposes a numerical approach, seeking to better predict and understand the structural mechanical behaviors and failure patterns of reinforced recycled aggregate concrete slabs with and without steel fiber. Based on the finite element method, an appropriated constitutive damage model is employed to represent the nonlinear behavior of the conventional/recycled concrete, while an elastic-perfectly plastic model is used to describe the mechanical behavior of the reinforcements. To couple the independent FE meshes and incorporate the mutual interaction between the different components, rigid and non-rigid coupling technique is used to represent the perfect adherence or the bond-slip behavior. Seven concrete slabs were numerically analyzed either with different percentages of recycled aggregate replacement (0, 50 and 100%) or steel fibers content (0.0, 0.5 and 1.0%) and the results were compared with the experimental ones. The results showed that the applied methodology is capable of simulating with good accuracy the punching shear failure mechanism of the slabs. It was observed that the punching ultimate load decreased with increase of recycled aggregate content, as well as that the steel fiber addition can minimize the negative effects of recycled aggregate employment.

The use of construction and rubber recycled material for the production of cement composites with thermal insulation function

This article presents the results of the possible use of construction waste and rubber granulate as a filler substitute for the production of cement composites with thermal insulation properties. It describes the individual components of the materials necessary for the designing of recipes and their properties. The article presents the thermal insulation properties and strength characteristics of the designed recipes of non-traditional cement composite after 7, 14, 28 and 90 days.

Permeability of concrete with recycled aggregate coating treatment

The effective use of construction waste is of great significance to the construction of a sustainable society. This study investigated the permeability of recycled aggregate concrete with different qualities. The recycled aggregates were treated with crystallizing agent. The improvement effect of crystallization was evaluated by rapid chloride ion migration test and electron microscope observation. The results show that calcium silicate hydrate was generated by the reaction of crystallizer and hydration product in the adhesive mortar, which effectively improves the chloride ion impermeability of reclaimed aggregate concrete.

Use of construction waste to modify soil grading for compressed stabilized earth blocks (CSEB) production

Earthen materials have been used in civil engineering construction worldwide with different forms, such as mud, adobe, rammed earth and bricks. Compressed stabilized earth blocks (CSEB) can be considered as a new member of the earthen building material family. Also, it can overcome the problems associated with fired bricks and cement blocks. Cement is the most commonly used as stabilizers to enhance the properties of CSEB. The governing factor which controls the properties of CSEB is the amount of clay content in the soil. Researches have concluded that about 25% of clay and silt (finer) content contributes to high compressive strength. However, controlling of larger particles is not addressed much. This study focused on controlling the finer content as well as larger particles with the use of construction waste (mostly with crushed concrete) and river sand. Selected soil was modified to get the finer content as 5%, 10%, 15% and 20%. This modification was done by adding river sand and construction waste to the soil to optimize the particle packing based on particle packing theories. Cement was used as the stabilizer with 6%, 8%, and 10%. (150 × 150 × 150) mm3 cubes were cast and tested for dry density, water absorption, 28 days wet and dry compressive strength, accelerated erosion and compared with SLS 1382; part 2 requirements. Block properties were conformed with SLS 1382 requirement when finer contents are 10% and 5% with 10% and 8% cement. Further, Industrial-scale blocks of (350 × 100 × 175) mm3 made with 10% finer and 8% cement satisfied the Grade 1 block properties. CSEB made mixing with construction waste contributes to manage the environmental pollution due to construction waste while giving a fair solution to the problem with the shortage of building materials.

Aging of recycled aggregates mortars by drying-wetting cycles

Due to the large amount of CO2 emissions produced nowadays by the construction sector, the scientific community is looking for measures that will bring constructions to the be as environmental-friendly as possible. One of the most popular lines of research is the use of construction waste as recycled aggregates for the production of recycled aggregates concrete. Regarding the use of coarse recycled aggregates, there are a large number of studies that validate their use at both a mechanical and durability levels. Regarding the use of fine particles, which are inherent to the existence of coarse particles, it is necessary to increase the existing knowledge before they can be widely used. In this paper, the authors have sought to isolate the weakest part of those concrete mixes with exclusively recycled aggregate, i.e. a mortar made exclusively with fine recycled aggregates, in order to analyse the effect of drying-wetting cycles on mixes with recycled aggregates only. Specifically, three types of fine aggregates were used, one natural silica aggregate, one aggregate from crushed ballast and one from crushed sleepers. The mortars made with these aggregates were subjected to 50 durability cycles in distilled water, seawater and water with sulphates. Mechanical, visual and microstructural tests were carried out to analyse the effect of each of these environments on each of the mortars.

EFFECT OF CRUSHED DOUM PALM SHELL AS PARTIAL REPLACEMENT OF COARSE AGGREGATE IN CONCRETE

The use of alternative materials in place of natural aggregate in concrete production has been getting attention all around the globe; this makes concrete a sustainable and environmentally friendly construction material. In this study the use of crushed doum palm shell (CDPS) as partial replacement for coarse aggregate in concrete production was investigated. The concrete grade 30 was used for the research with a water /cement ratio of 0.45. The control sample contained normal concrete ingredient cement, fine aggregate and coarse aggregate. The CDPS replacement by weight was varied at 5%, 10%, 15%, 20%, and 25% respectively for the test sample. The 28-day compressive strength of the concrete using Doum palm shell aggregate was found to be 28.0 and 20.2 MPa at 5 and 10% replacement under full water curing and it satisfies the requirement for structural lightweight concrete which was more than 17MPa. The study recommended replacement of coarse aggregate up to a maximum of 10 % crushed doum palm shell for structural light weight concrete and it encourage the use of agricultural wastes in construction as an environmental protection and cost reduction measure. However, results from laboratory investigations indicated that crushed doum palm shell (CDPS) has good potential as a coarse aggregate for production of structural lightweight concrete, especially for low-cost housing and also for use in earthquake prone areas.

Acoustic barrier simulation of construction and demolition waste: A sustainable approach to the control of environmental noise

The use of construction waste to build noise barriers is a considerable reason in determining sustainability and environmental noise control. The present study aims to analyze the sound absorption coefficient of concrete blocks from construction and demolition waste (CDW), to apply in computer simulation of noise barrier in urban area. Thus, the research presents a double environmental aspect, on the one hand, the reduction of sound pressure levels from road traffic noise and, on the other hand, the recycling of construction by-products. The sound absorption coefficient was characterized by normal incidence. To obtain the attenuation behavior of the barrier, the new sound absorption coefficient of the material was inserted in the SoundPlan database, acoustic prediction software. The results showed that the insertion of a simple barrier from construction and demolition waste (CDW) is advisable to reduce noise outdoors. As for concrete blocks from CDW for the building of noise barriers can become a sustainable alternative, mitigating the sound impact and/or the environmental impact. Current trends are oriented towards finding alternative sustainable materials for concrete, one example is the recycling of waste from construction by-products.

Use of construction materials to improve the properties of clay soil

The demolition of old buildings, construction, and rebuilding processes leave a waste called the so-called construction waste. For the save the environment and its aesthetics, as well as for the economic and financial benefit from these wastes, as well as for the removal of all obstacles that may affect the continuity of work, so there was a joint responsibility of several parties, including the municipalities in addition to the party responsible for the construction process, which may be individuals or Construction companies contribute to the disposal and possible utilization of these wastes at the same time, and thus this has led to the joint responsibility of several parties and parties in recycling these wastes. This research paper presents a study in the Use of construction waste to improve the properties of clay soil, by taking samples from the location of a building under construction in the city center of Hilla / Iraq. where we mixed it with ceramic powder.

Use of construction materials to improve the properties of clay soil

The demolition of old buildings, construction, and rebuilding processes leave a waste called the so-called construction waste. For the save the environment and its aesthetics, as well as for the economic and financial benefit from these wastes, as well as for the removal of all obstacles that may affect the continuity of work, so there was a joint responsibility of several parties, including the municipalities in addition to the party responsible for the construction process, which may be individuals or Construction companies contribute to the disposal and possible utilization of these wastes at the same time, and thus this has led to the joint responsibility of several parties and parties in recycling these wastes. This research paper presents a study in the Use of construction waste to improve the properties of clay soil, by taking samples from the location of a building under construction in the city center of Hilla / Iraq. where we mixed it with ceramic powder.

Preliminary Analysis of the Use of Construction Waste to Replace Conventional Aggregates in Concrete

This work aims to study the influence of using construction and demolition waste in the replacement of coarse and fine aggregate to produce recycled aggregate concrete (RAC). A moderate compressive strength concrete made with usual fine and coarse aggregate was used as a benchmark material. Compressive and split tensile tests were performed using 120 cylindrical concrete specimens with 150 mm diameter and 300 mm length. Four-point flexural tests in reinforced beams made with conventional concrete and RAC were performed. The results obtained showed that the use of recycled fine aggregates, in both percentages of substitution investigated—50% and 100%—did not generate any deleterious influence on the values of compressive strength and split tensile strength of the RACs produced. Tin fact, the mechanical strengths of RACs produced with recycled fine aggregate were equal or higher than those from the reference concrete. The same behavior was not observed, however, when the recycled coarse aggregate was used. For this case, decreases in concrete mechanical strengths were observed, especially in compressive strength, with values around 35% lower when compared to the reference concrete. Tensile mechanical tests results confirmed the excellent behavior of all RACs made with replacement of usual fine aggregates by recycled. Bending tests performed in reinforced RAC beams had as objective to evaluate the deformation profile of the beams. The obtained results showed that RAC beams with full replacement of usual fine aggregate by the recycled aggregates have presented little changes in the global behavior, an aspect that encourages its use.

Rational use of construction waste taking into account environmental factors

Rational use of construction waste taking into account environmental factors

APPLICATION OF THE CONSTRUCTION WASTE AS A REDUCING AGENT IN THE SOLUBILITY OF IRON TAILING METALS

Iron ore tailings has acid pH and high content of metals, such as iron, aluminum and manganese. Regarding the environment, these metals poses a risk of contaminating the soil and underground water. Yet, construction residues usually have high pH and because of this, they can be used to neutralize soil acidity and to reduce metal availability in mining tailing piles. The objective of this study was to evaluate the aplicabilith of CW to promote neutralization of the acidity in iron ore tailings aiming at decreasing the solubility and mobilith of metal found in them. Thus, a sample of construction waste was collected and characterized which was later incorporated at different doses into a sample of iron mining tailing collected in the Iron Quadrangle (Minas Gerais – Brazil). The construction waste raised the pH of the tailing sample from 5.58 to 8.22. Moreover, the incorporation of the waste incorporation decreased the manganese solubility in at least 80%. Despite the lack of national legislations and policies on the use of construction waste for this purpose, the results show that it is a promising technological alternative.