Feasibility study of using brick made from municipal solid waste incinerator fly ash slag

This study deals with the effect of MSWI slag on fired clay bricks. Brick samples were heated to temperatures which varied from 800 to 1,000 degrees C for 6h, with a heating rate of 10 degrees C/min. The material properties of the resultant material then determined, including speciation variation, loss on ignition, shrinkage, bulk density, 24-h absorption rate and compressive strength. Toxicity Characteristic Leaching Procedure tests were also conducted. The results indicate that the heavy metal concentrations in the leachates met the current regulatory thresholds. Increasing the amount of MSWI slag resulted in a decrease in the water absorption rate and an increase in the compressive strength of the MSWI-slag bricks. The 24-h absorption rate and compressive strength of the MSWI-slag brick made from samples containing slag sintered at 1,000 degrees C all met the Chinese National Standard (CNS) building requirements for second-class brick. The addition of MSWI slag to the mixture reduced the degree of firing shrinkage. This indicates that MSWI slag is indeed suitable for the partial replacement of clay in bricks.     

Study on the characteristics of building bricks produced from reservoir sediment

This research investigates the feasibility of building bricks produced from reservoir sediment sintering using various sintering temperatures and clay additions. The experimental results indicate that sintered specimen densification occurred at sintering temperatures of 1050-1100 degrees C. Increasing the sintering temperature decreases the water absorption and increases the shrinkage, density and compressive strength of sintered specimens. The experiments were conducted at a temperature ranged from 1050 to 1150 degrees C with clay addition contents varying from 0% to 20%. All sintered specimens made from reservoir sediment were in compliance with Taiwan building bricks criteria. This means that raw materials for producing building bricks can be replaced with reservoir sediment. The metals concentrations of the leachate from the toxicity characteristics leaching procedure (TCLP) test are all complying with the current regulatory limits. These results confirm the feasibility of using reservoir sediment to produce sintered construction brick.     

Influence of the design materials on the mechanical and physical properties of repair mortars of historic buildings

Historic buildings are subjected to deterioration by natural weathering or by corrosion due to polluted atmosphere and the materials more susceptible are the mortars used. This study examines the influence of the type and quantity of design materials on compressive strength, creep, water absorption and length change of repair mortars produced. The design materials used were lime, natural pozzolan, sand and brick fragments in order to obtain the compatibility required between historic and repair mortars; different quantities of Portland cement were also used in order to quantify his influence. Nine mixtures were then designed and produced considering as parameters two binder: aggregates ratios, three pozzolan: cement ratios and three sand: brick fragments ratios. The experimental measurements continued until the age of 3 years or the stabilization of the test values. The results indicate that compressive strength is strongly affected by cement content and aggregates dosage and type. It appears that the increase of cement as well as brick fragments leads to confinement of creep deformation, while the mixtures with high pozzolan and sand content experience considerably high creep values. Water absorption reaches higher values when pozzolan or aggregate dosage arises and brick is in excess. Shrinkage increases when binder or brick quantity arise and is considerably influenced by cement content.     

An application of blended fly ash and residual rice husk ash for producing green building bricks

The present study investigates the possibility of using a blended class-F fly ash (FA) and residual rice husk ash (RHA) in the production of green building bricks through the application of densified mixture design algorithm (DMDA) in order to provide a new use for solid waste materials. This study uses unground rice husk ash (URHA) as a partial fine aggregate substitution (10–40%) in the studied cementitious mixtures. Solid bricks of 220 × 105 × 60 mm in size were prepared under forming pressure of 25–35 MPa, a curing temperature of 90 °C, and a relative humidity of 50%, for tests that assessed: compressive strength, flexural strength, bulk density, void volume, and water absorption. The test results showed that all brick samples demonstrated excellent properties. Compressive strength and flexural strength ranged, respectively, between 20.2–33 MPa and 5.4–6.9 MPa. Additionally, up to 30% of URHA content, the values of water absorption and void volume ranged, respectively, between 8.8–15.7% and 1.5–2.1%. All of these values not only conformed well to the requirements of the Vietnamese codes but also demonstrated great potential for using a blended FA–RHA in producing green building bricks.     

Development of bio-cemented constructional materials through microbial induced calcite precipitation

Microbial induced calcite precipitation (MICP) is an environmentally friendly technology to bond sand particle together to form sandstone like materials. In this paper, MICP-treated bio-specimen was developed through MICP. The property of bio-specimen was compared with beams or bricks made through lime modification and cement modification. Ottawa sand was used in MICP-treated bio-specimen preparation. The proportion of lime or cement was in the range of 10–40% by weight of dry sand. The four-point bending tests, brick compression tests and unconfined compression tests were conducted. The test results indicated that flexure strength of MICP-treated bio-specimen was 950 kPa which was similar to flexure strength of 20–25% cement-treated sand beams, but was much higher than flexure strength of 30% lime-treated sand beams. The brick compression strength of MICP-treated bio-specimen achieved 500 kPa, which was similar to brick compression strength of 30% lime-treated sand bricks. The unconfined compression test results showed that the unconfined compression strength (UCS) of MICP-treated bio-specimen (1300 kPa) was higher than UCS of 10% cement-treated specimen (900 kPa), and much higher than UCS of lime-treated sample (around 140 kPa). The relative uniformity of precipitated CaCO₃ distribution was achieved through the sample immersing preparation method. SEM images showed that failure pattern of MICP-treated, cement-treated and lime-treated specimens were bond-particle failure.     

The use of the Novosol process for the treatment of polluted marine sediment

The work presented in this article concerns polluted marine sediments. The article is divided into three parts. The first part discusses existing industrial procedures of treatment. The second part introduces the Novosol((R)) process, which was used for the treatment of polluted marine sediments. This process is based on the stabilization of heavy metals in the solid matrix by phosphatation and the destruction of organic matter by calcination. Finally, after a comparison had been made between environmental results obtained on both polluted marine sediments and inert ones, treated sediments were introduced in the production of clay bricks. The results obtained show that the Novosol process leads to the immobilization of most heavy metals and can be considered as an efficient tool for the stabilisation of polluted marine sediment. Thus, the results of physical and mechanical tests as compressive strength and water absorption indicate that performances obtained were comparable to standard brick values. These results confirm that, once treated, polluted sediments can be recycled.     

Effect of rice husk ash on the properties of bricks made from fired lateritic soil-clay mix

The effects of rice husk ash (RHA) on the various properties of lateritic soil-clay mixed bricks were studied. The effect of firing duration (at a firing temperature of 1000°C) on the properties of bricks was also studied. The measured properties were linear shrinkage, unit weight, compressive strength, 24-hour immersion water absorption and 5-hour boiling water absorption. Both linear shrinkage and unit weight of bricks decreased with increase in the percentage of RHA content. The compressive strength of lateritic soil-clay mixed bricks increased almost linearly with increase in the percentage content of RHA. The bricks which received a 4-hour at 1000°C attained maximum compressive strength. Both 24-hour immersion and 5-hour boiling water absorptions of the bricks were within the permissible limits. The strengths of the bricks were compared with British statutory minimum compressive strengths of bricks for various walls. The bricks are recommended or load-bearing walls.     

Use of TEOS for fired-clay bricks consolidation

Ethyl silicate (tetraethylorthosilicate, TEOS) is one of the most used consolidants for natural stones in the restoration of architectural and cultural heritage and the literature concerning its performance in this application is quite abundant. In this paper, the need, and sometimes urgency, of preserving ancient fired-clay elements (bricks and terracotta decorations) is highlighted as well, and the effects of ethyl silicate consolidation (75 wt% TEOS in white spirit) are investigated from a microstructural, physical–mechanical and aesthetic point of view. Fired-clay brick samples (open porosity ≈45 %; compressive strength ≈14 N/mm²) were treated and then characterized by mercury intrusion porosimetry, scanning electron microscopy, water absorption, compressive strength test and spectrophotometry, to assess the effects of the treatment. The TEOS treatment gave encouraging results: a good penetration depth (about 10 mm), a limited reduction in porosity, a large decrease in water absorption, a significant improvement in compressive strength and a positive aesthetic outcome. The results obtained pointed out TEOS treatment as a promising solution for fired-clay bricks consolidation.     

Zerstörungsarme Bestimmung der Steindruckfestigkeit von Bestandsmauerwerk aus Hochlochziegeln

Non‐destructive determination of the compressive strength in existing masonry made of vertically perforated bricks Urban consolidation and the conservation of listed buildings often require measures to determine the structural stability of the existing masonry. The key parameter for the static proof is the compressive strength of the masonry, which consists of the compressive strength of the bricks and the compressive strength of the mortar bed. So far, no testing methods have been developed that do not significantly interfere with the static load bearing capacity of masonry made of vertically perforated bricks and which make it possible to determine the compressive strength by analysing parts of the bricks. This article presents a non‐destructive test method to determine the compressive strength of vertically perforated bricks of existing masonry. This test method only uses small test specimens taken from parts of the bricks. As a result, the static load bearing capacity of the existing masonry is hardly affected. The results of these tests show that it is possible to establish a plausible correlation between the comprehensive strength of the brick and the compressive strength of the small test specimens. On this basis, a concept for a non‐destructive testing method which makes the determination of the compressive strength of vertically perforated bricks in existing buildings possible is presented.     

Limestone dust and glass powder wastes as new brick material

Large amounts of glass and limestone wastes are accumulating all over the world. Disposal of Limestone Powder Waste (LPW) and Waste Glass Powder (WGP) is a rapidly growing problem for some municipalities, so research for alternative utilization of these disposals is needed. In this respect, the objectives of this study are to investigate both physical and mechanical properties of samples containing LPW–WGP combinations for producing as new building brick material. An experimental approach to develop a new brick material including mainly LPW, a small quantity of Portland cement and WGP is presented. The LPW, WGP and cement are mixed, humidified and compacted under high pressure in the moulds. The values of compressive strength, flexural strength, unit weight, water absorption, abrasion resistance, freezing–thawing (F-T) resistance and thermal conductivity satisfy the relevant international standards and introduces smoother surface compared to the current concrete bricks in the market. The process undertaken can easily be applied within the current brick plants. The WGP used in LPW remarkably improves the compressive strength, flexural strength, modulus of elasticity, abrasion resistance, F-T resistance, and thermal conductivity of LPW brick samples produced in this study. The test results indicate that the samples containing LPW–WGP combinations provide better results for a potential of producing economical new brick materials.     

Experimental research of masonry compressive strength in the Auschwitz II - Birkenau former death camp buildings

The paper presents the results of strength tests of brick masonry in 14 prisoner barracks located at the Auschwitz II-Birkenau former death camp. These buildings were constructed in a few months in 1941, that is in the initial phase of the extermination camp. Strength tests were conducted as part of a broad program whose purpose was to document the condition of the camp buildings being invaluable historical material objects. Due to the nature of the historical buildings a broad program has been consulted with the services of conservation. Strength tests of masonry and masonry materials (bricks and mortars) were performed on small-diameter core samples cut from the original structures of buildings in the camp. In addition, comparative tests were carried out on samples made in the laboratory. Results and their analysis made it possible to estimate the compressive strength of masonry, bricks and mortars in the brick buildings erected more than 70 years ago. The performed documentation of brick walls and identification of strength parameters are an important stage of the planned preservation process, the ultimate goal is to preserve the historic buildings for future generations.     

Evaluation of properties of bricks impregnated with sulphur

Locally produced raw sulphur was used as an impregnant due to its availability at relatively low cost. For both laboratory prepared samples and factory brick, sulphur impregnation at atmospheric pressure produces significant improvements in water absorption, compressive strength and most physical properties. Simple equations were developed, from which the sulphur loading required for any desired water absorption of the treated brick can be predicted accurately if the initial water absorption value of the sample is known.     

免烧多孔吸声砖制备的研究

研究用不同种类的天然石英砂和黏结剂为主要原料,采用压制成型的工艺,在常温下制成了免烧多孔吸声砖。主要考察石英砂种类、骨料与黏结剂的质量比、样品厚度以及样品背后空腔对吸声性能的影响。研究表明：当石英砂为黑砂4号,黑砂与黏结剂的质量此为30：1,厚度为100mm时,对其采用驻波管法进行吸声系数的测试,其平均吸声系数可达到68％,混响法可达到88％。     

The effects of pre and post construction moisture condition on the in-plane and out-of-plane strengths of brick walls

An important factor affecting the strength of a masonry wall is the capacity of the bond between the mortar and the bricks to transfer the loads within the wall. The main parameter influencing the bond strength is the moisture content of the brick units and the consistency of mortar paste at the time of construction. Another important, but little known, factor is the post-construction moisture curing of the wall. In this paper, the results of a series of standard tests, aimed at determining the effects of moisture condition on the flexural strength, direct tensile bond strength, shear bond strength, compressive strength and diagonal shear strength of brick masonry are presented. The results indicate a substantial increase in the bond strength when saturated, surface dry, brick units are used and show the favorable effects of post-construction water curing of brickwork. Also, in-plane shear and out-of-plane bending tests are carried out on a number of brick wallets and infills, constructed with different pre and post construction moisture conditions and results are compared to drive at quantitative conclusions on the effects of pre-wetting the brick units at the time of construction and post-construction moisture curing on the behavior and strength properties of brick wall construction.     

Thermal Transmittance of Porous Hollow Clay Brick by Guarded Hot Box Method

The thermal property of a porous hollow clay brick was determined by measuring the thermal transmittance of the wall made of porous hollow clay bricks. Prior to the production of porous hollow clay bricks, nonporous and porous tiny clay bricks were prepared to determine the physico-mechanical properties by modifying the amount of wood flour and firing temperature. The bricks were produced by uniaxial pressing and then fired in an electric furnace. Their physico-mechanical properties were measured by water absorption, apparent porosity, bulk density, and compressive strength. The porous tiny clay bricks were produced with three types of wood flour: coarse wood flour (1–0.36 mm), medium-sized wood flour (0.36–0.15 mm), and fine wood flour (< 0.08 mm). The thermal transmittance of porous hollow clay bricks was determined through the guarded hot box method, which measures the wall made of porous hollow clay bricks and nonporous cement bricks. The two walls had a thermal transmittance of 1.42 and 2.72 \(\hbox {W}\cdot \hbox {m}^{-2}\cdot \hbox {K}^{-1}\), respectively. The difference in thermal transmittance was due to the pores created with fine wood flour (< 0.08 mm) as a pore-forming agent.     

Mechanical behavior of masonry assemblages manufactured with recycled-aggregate mortars

Mortars containing recycled aggregate, instead of quartz sand, were characterized to find an alternative application for the fine recycled-aggregate fraction coming from building debris processing. Tests on bond strength of mortar to masonry units were carried out, as well as tests on compressive and shear strengths of masonry assemblages. The results obtained were related to the mechanical properties of mortars and brick. On the basis of the characterization results and performance evaluations, recycled-aggregate mortar appears to be superior to ordinary mortars in terms of mortar–brick bond strength and shear strength of masonry assemblages. This improved performance is of particular interest for the masonry structures in zones of seismic activity. In addition, the use of fine recycled aggregate is in accordance with the sustainable development concept, where recycling of building rubble plays a key role in ending the building life cycle.     

Durability of lightweight masonry mortars made with white recycled polyurethane foam

Masonry mortars made with Portland cement, sand, water and white recycled polyurethane foam from industrial waste are examined in this study. Different mixtures were firstly prepared through the substitution of different amounts of sand by equivalent volumes of polyurethane and then, with different ratios of cement/aggregates. The comparative study was carried out on the effect that different ageing tests have on the mechanical properties of these mortars under flexion and compression. For this purpose, the samples were exposed to different corrosion and hardness tests: resistance to dry heat, hot water, salt spray test and Kesternich testing. After ageing, a small reduction in compressive strength was observed. However, in all the samples, the strength values were sufficiently high to consider that these types of recycled materials remain practically unaffected when compared with the reference specimens. Finally, alkali-silica reaction tests were performed to determine the chemical stability of these mortars.     

Durability of lightweight masonry mortars made with white recycled polyurethane foam

Masonry mortars made with Portland cement, sand, water and white recycled polyurethane foam from industrial waste are examined in this study. Different mixtures were firstly prepared through the substitution of different amounts of sand by equivalent volumes of polyurethane and then, with different ratios of cement/aggregates. The comparative study was carried out on the effect that different ageing tests have on the mechanical properties of these mortars under flexion and compression. For this purpose, the samples were exposed to different corrosion and hardness tests: resistance to dry heat, hot water, salt spray test and Kesternich testing. After ageing, a small reduction in compressive strength was observed. However, in all the samples, the strength values were sufficiently high to consider that these types of recycled materials remain practically unaffected when compared with the reference specimens. Finally, alkali-silica reaction tests were performed to determine the chemical stability of these mortars.     

Briques silico-calcaires autoclavées: influence de l’addition de laitier de haut fourneau sur la formation des phases

The mechanical properties of sand-lime bricks produced by autoclaving under different conditions and incorporation of granulated slag have been investigated previously. In this study, the relationship is established between the structure, the phases formed and the strength. Based lime and granulated slag a new binder is developed. This is cured at saturated vapour pressures of 1.0 and 1.8 MPa. The results showed a decrease in compressive strength due to the substitution. The microstructure analysis showed that reaction products consist mainly of 11 Å tobermorite and xonotlite. Also, when increasing the autoclave temperature, it results in an increase in xonotlite relative to tobermorite. The X-ray diffractions of these phases are very low, hardly visible; they are masked by the presence of quartz. Their intensities increase with the presence of slag. The slag seems more reactive with lime than quartz. Observations with the scanning electron microscope allow better to appreciate these phases. By its composition to amorphous structure, the granulated slag does not release new distinct phases of hydrates.     

Reuse of spent catalyst as fine aggregate in cement mortar

This study examined the feasibility of reusing spent zeolite catalyst, after fluidized catalytic cracking, as a substitute for fine aggregate (sand) in cement mortars. The tested result shows that spent catalyst can replace up to 10% of fine aggregate without decreasing the mortar strength. In fact, the substituted mortars show higher compressive strength than the unsubstituted samples. The flowability of the fresh mortars decreases with increasing substitution level and the mortars incorporated with spent catalyst show less bleeding. In the hardened state, the water absorption of the resulting mortar increases with longer curing age, higher substitution level and smaller water-to-cement (W/C) ratio. Toxicity characteristic leaching procedure (TCLP) analysis confirms that the spent catalyst meets the standard, and thus should be classified as general non-hazardous industrial waste.