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Reuse of construction and demolition (C&D) waste as aggregates is becoming increasingly popular for a number of environmental and economic reasons. The purpose of this paper is to explore this topic.

In this study, structural‐ and pavement‐grade portland cement concrete (PCC) mixtures were developed using crushed recycled brick masonry from a demolition site as a replacement for conventional coarse aggregate. Prior to developing concrete mixtures, testing was performed to determine properties of whole clay brick and tile, as well as the crushed recycled brick masonry aggregate (RBMA), and a database of material properties was developed.

Concrete mixtures exhibiting acceptable workability and other fresh concrete properties were obtained, and tests were performed to assess mechanical properties and durability performance of the hardened concrete. Results indicated that recycled brick masonry aggregate concrete (RBMAC) mixtures can exhibit mechanical properties comparable to that of structural‐ and pavement‐grade PCC containing conventional coarse aggregates.

Results for durability performance were mixed, but additional testing to evaluate durability performance is recommended.

Although RBMAC has been untested in field applications, results of laboratory studies performed to date indicate that this material shows promise for use in pavement and structural applications. Future testing of RBMAC in both laboratory and field settings will allow stakeholders to gain a comfort level with its properties, identify specific potential uses, and establish guidelines that will assist in ensuring acceptable service life performance.

From the standpoint of sustainability, use of recycled materials as aggregates provides several advantages. Landfill space used for disposal is decreased, and existing natural aggregate sources are not as quickly depleted. Use of recycled aggregates in lieu of virgin quarried aggregates can potentially result in a lower embodied energy of the concrete, although this is often dependent on hauling costs. This particularly holds true if the methodology used to compute the embodied energy of a structure accounts for the “recovery” of energy at the end of its service life.

Based on the shake table test on "tie column-ring beam-cast-in-place slab" construction waste recycled brick masonry structure, a 1/3 scaled model of 4 stories is tested to analyze the seismic behavior of the multi-storey masonry structure. The test is conducted with EL-Centro seismic wave, Taft wave and artificial wave to simulate the damages observed and the seismic response under different earthquake levels. On the basis of test results, the seismic performance of the model is good and the overall structure could satisfy seismic fortification requirements in the region of intensity 8. At the same time, there was no obvious difference between this masonry structure and recycled aggregate concrete block masonry structure. The lintel of the door and window damage seriously. The base damages more easily than the superstructure. Masonry structure with construction waste recycled brick can satisfy the requirement of the masonry structure buildings in eight degree of aseismatic design area.

Recycled concrete is an economical and environmentally friendly green material. The shear performance of recycled concrete load-bearing masonry is studied, which is great of significance for its promotion and application and also has great significance for the sustainable development of energy materials.

In total, 30 new load-bearing block masonry samples of self-insulating recycled concrete are subjected to pure shear tests, and 42 samples are tested subjected to shear-compression composite shear tests. According to the axial design compression ratio, the test is separated into seven working conditions (0.1–0.8).

According to the test results, the recommended formula for the average shear strength along the joint section of recycled concrete block masonry is given, which can be used as a reference for engineering design. The measured shear-compression correlation curves of recycled concrete block masonry are drawn, and the proposed limits of three shear-compression failure characteristics are given. The recommended formula for the average shear strength of masonry under the theory of shear-friction with variable friction coefficient is given, providing a valuable reference for the formulation of relevant specifications and practical engineering design.

Simulated elastoplastic analysis and finite element modeling on the specimens are performed to verify the test results.

Introduction In a recent paper in this journal, Campbell outlined some of the techniques and problems associated with the demolition of existing structures and touched upon the possibility of recycling the debris from this process. This reflects the growing awareness among the general public, local authorities and central Government that the recycling of waste materials, from all sources, is both necessary and desirable. Indeed, according to a recently published report from the Trade and Industry Committee of the House of Commons: ‘The benefits of recycling are obvious: rarely do environ‐mental and economic factors so unambiguously support the same goal’.

The purpose of this paper is to investigate whether concrete that includes un‐graded recycled aggregates can be manufactured to a comparable strength to concrete manufactured from virgin aggregates.

A paired comparison test was used to evaluate the difference between concrete made with virgin aggregates (plain control) and concrete including recycled waste. Un‐graded construction demolition waste and un‐graded ground glass were used as aggregate replacements. With regard to concrete, compressive strength is widely used as a measure of suitability as being fit for purpose. Therefore compressive strength was mainly used to compare the different concrete batches; however density was measured across the range of samples.

The findings show that a lower average compressive strength is achieved when compared to the plain control sample manufactured with virgin aggregates. Correct particle packing may not be achieved and grading of aggregates is essential prior to mix design. The recycled aggregate was highly variable in terms of the fine particle content, which affected the water demand of the concrete.

This manufacturing practice is considered necessary because of the current trend in using waste products in concrete to replace binders and aggregates; thus reducing the impact on the environment and use of finite natural resources. The research shows the risk of mixing concrete using a simple aggregate replacement without careful aggregate grading and adjustments to the mix design.

The paper examines 100 per cent ungraded aggregate replacement with glass and demolition waste.

This study investigates the carbon footprint of the alternative structure types and materials used for the reconstruction of schools in Haiti. Are recycled construction materials more environmental than virgin materials? To estimate which alternative construction solution has the smallest carbon footprint, a survey was made for the school model used for the reconstruction programme in Haiti after the 2010 earthquake.

The carbon footprint was calculated using life cycle assessment methodology for five different concrete structure alternatives and five different cement mixes for the same design of a school building. In addition, the uptake of CO₂ through the carbonation of concrete during 50 years was calculated.

The carbon footprint of recycled materials can be either the best or worst option, depending on how the materials are used. The difference to using virgin materials is not big. This is mainly due to the lower structural performance of recycled materials, which needs to be compensated for by using additional reinforcements. Using cement mixes that have high amounts of substitutes for cement seems to lower the carbon footprint of structures considerably. The uptake of CO₂ in carbonation has potential but requires an optimal design and environment.

The findings give information for humanitarian project managers and designers on lowering the carbon footprint of their construction projects.

The objective of this research is to evaluate the influence of mineral additions on the mechanical performances of polymer concrete. This study aims to propose a novel approach formulation of polymer concrete based on reduction in the quantity of the binder and disposal of large quantities of industrial by-products and household waste such as the marble, the brick and silica fume whose valuation in polymer concrete could be an interesting ecological and economical alternative. The incorporation of a rate of 10% brick powder affects the distribution of pores inside polymer concrete, that is, the pore diameters become thinner and decrease and the porosity becomes evenly distributed. The recycled mineral brick powder addition in polymer concrete mix improved the mechanical properties.

This polymer concrete was prepared by using polyester resin and two different types of sand, following a new formulation based on an empirical method. Furthermore, the optimal binder percentage was of 20% resin and a mixture of 52% dune sand and 48% quarry sand according to the Abrams method. To achieve our objective, five rates (from 2% to 10%) of brick powder, marble powder and silica fume were examined. Afterwards, its mechanical characteristics were evaluated via a three-point flexural with compressive resistance. The findings indicated that the addition of brick, marble and silica fume to polymer concrete increases the flexural strength with 21.84%, 12.76% and 9.07%, respectively.

Concerning the compressive strength, the best resistance is that of polymer concretes based on brick powder, and this economic formulation of polymer concrete serves the optimal cost/resistance ratio criteria. It allows an improvement in the mechanical resistance of concrete are obtained by adding brick powder that exceed that of the reference concrete.

In the past few decades, there has been several contribution concerning the subject of the reduction of the binder quantity in polymer concretes and adding the industrial and household wastes. However, previous studies revolving around the same area disregarded the effect of the brick powder, which appears scientifically of great importance for enriching the literature.

This paper presents the details of a research study on developing composite masonry blocks using two types of mixes, conventional and lightweight mix, to enhance their fire/bushfire resistance and residual compressive strength.

Composite masonry blocks (390 × 190 × 90 mm) were fabricated using conventional cement–sand mix as the outer layer and lightweight cement–sand–diatomite mix as the inner layer. Material properties were determined, and all the mixes were proportioned by the absolute volume method. After 28 days of curing, density tests, compression tests before and after fire exposure and fire resistance tests of the developed blocks were conducted, and the results were compared with those of conventional cement–sand and cement–sand–diatomite blocks.

Developed composite blocks satisfy density and compressive strength requirements for loadbearing lightweight solid masonry units. Fire resistance of the composite block is –/120/120, and no cracks appeared on the ambient side surface of the block after 3 h of fire exposure. Residual strength of the composite block is higher compared to cement–sand and cement–sand–diatomite blocks and satisfies the loadbearing solid masonry unit strength requirements.

Composite block developed in this research can be suggested as a suitable loadbearing lightweight solid masonry block for several applications in buildings in bushfire prone areas.

Limited studies are available for composite masonry blocks in relation to their fire resistance and residual strength.

The purpose of this study is to advance the application of pulverised cow bone ash (PCBA) as a partial replacement of cement in soil stabilisation for the production of bricks. The study investigated the impact of PCBA substitution on the characteristic strength of clay bricks under variant curing media.

Dried cow bones were pulverised, and an energy-dispersive X-ray fluorescence test was conducted on PCBA samples to determine the chemical constituents and ascertain the pozzolanic characteristics. Ordinary Portland cement (OPC) and PCBA were blended at 100%, 75%, 50%, 25% and 0% of cement substitution by mass to stabilise lateritic clay at 10% total binder content for the production of bricks. The binder-to-lateritic clay matrixes were used to produce clay bricks and cylinders for compressive and splitting tensile strength tests, respectively.

The study found that PCBA and OPC have similar chemical compositions. The strength of the clay bricks increased with curing age, and the thermal curing of clay bricks positively impacted the strength development. The study established that PCBA is a suitable substitute for cement, up to 25% for stabilisation in clay brick production.

Construction stakeholders can successfully use a PCBA-OPC binder blend of 1:3 to stabilise clay at 10% total binder content for the production of bricks. The stabilised clay bricks should be cured at an elevated temperature of approximately 90°C for 48 h to achieve satisfactory performance.

The PCBA-OPC binder blend provides adequate soil stabilisation for the production of clay bricks and curing the clay bricks at elevated temperature. This aspect of the biomass/OPC binder blend has not been explored for brick production, and this is important for the reduction of the environmental impacts of cement production and waste from abattoirs.

The purpose of this paper is to focus on optimization of recycling of concrete from lightweight aggregates containing expanded glass and hard polyurethane (PU) and on the issue of importance of environmental management in constructions, to produce the new combination using rest, construction waste of concrete from lightweight aggregates and hard PU new raw components of concrete from lightweight aggregates, as key reactive materials.

The research for this paper is based on the collection and analysis of quantitative and qualitative data, non‐linear programming (NLP) model and experimental research.

Results from the new recycled material have been compared with the normal existing concrete from lightweight aggregates. Characteristics of recycled lightweight concrete (LWC) such as density, compressive strength and thermal conductivity have been investigated and have been compared with normal existing concrete from lightweight aggregates. Results indicate that it is possible to recycle LWC aggregates and hard PU waste.

Research was limited to management of construction.

The use of waste LWC with aggregates containing expanded glass and hard PU seems to be necessary for the production of cheaper and environment‐friendly LWC.

The method shows great possibilities for increasing use of construction waste materials from LWC containing expanded glass and hard PU in order to benefit from the better use of existing construction waste. Characteristics such as density, compressive strength and thermal conductivity from the new recycled material have been compared with normal existing concrete from lightweight aggregates. They change depending on the type and part of waste as well as the type and part of fresh binding components. Thus, a new recycled material is created with new values of density, compressive strength and thermal conductivity, which conform to the compressive strength class and rules on heat protection and efficient use of energy in buildings (SI OJ RS No. 42/2002). Laboratory density, compressive strength and thermal conductivity tests results showed that LWC can be produced by the use of waste LWC with aggregates containing expanded glass and hard PU. The author proposes a model of recycling isolating materials, made of hard PU and LWC with aggregates containing expanded glass, based on recycling and NLP.