Design of an Energy-Efficient Pilot-Scale Pyrolysis Reactor Using Low-Cost Insulating Materials

Demolition of structure produces waste of clay bricks, which is usually disposal in landfills. Using the recycled waste made from crushed fired clay brick in concrete producing is a possible alternative and leads to a cleaner environment. This research describes experimental tests to evaluate using crushed fired clay brick waste as partial replacement of coarse aggregate in concrete mix. The compressive strength and the slump of concrete containing crushed clay brick aggregates partially replacing normal aggregates has been compared against concrete with normal gravel aggregates. Sixteen compressive tests on 150 mm cubes at 7 days and 210 days ages of concrete have been conducted. Coarse aggregates have been partially replaced by crushed clay brick at 25 percent of the weight. The amount of normal Portland cement (Type 1), water, and fine aggregate has not been changed. The results show that the compressive strength of concrete made with 25% clay brick aggregates has not shown a significant reduction in the compressive strength. Recycling crushed clay brick aggregates in concrete production can be a promising practice, which could reduce the cost and give better environmental aspects.

Clay brick is one of the major components of demolition waste, which is generally landfilled. Effective and new uses of recycled clay brick may provide sustainability benefits in terms of landfill reduction. Therefore, this research aims at applying Recycled fine clay brick aggregates (RFCBA) with sizes from 0.075 mm–4.75 mm to prepare Self-compacting concrete (SCC). The effects of RFCBA on fresh and hardened properties of SCC were investigated. Saturated surface dry RFCBA was used to replace Natural fine aggregate (NFA) with the percentage of 25%, 50%, 75% and 100%, respectively, in making the SCC mixes. Although experimental results showed that the flowability, passing ability, and segregation resistance of SCC containing RFCBA (RFCBA-SCC) decreased with the increasing RFCBA content, these properties still satisfy the criteria of SCC. The compressive strength, splitting strength, flexural strength, and elastic modulus of the RFCBA-SCC mixes decreased with an increase of RFCBA content. Due to their porous nature, recycled fine clay brick aggregates may also be a source of additional water for internal curing. The internal curing effect was confirmed by the mercury intrusion porosimetry, X-ray diffraction, and thermogravimetric analysis measurements. Moreover, a significant autogenous shrinkage reduction of SCC is achieved by using the RFCBA due to the release of additional water pre-stored in the RFCBA. Therefore, it can be concluded that the addition of RFCBA to SCC mixtures can provide additional practical benefits in the hardened state.

Catalytic pyrolysis, which combines catalytic cracking and steam pyrolysis, is a technique to process petroleum hydrocarbons. Catalytic pyrolysis has the advantages of both catalytic cracking and steam pyrolysis. It can raise the yields of light olefins, expand the flexibility of products distribution, and simultaneously lower reaction temperature and decrease energy consumption for the whole system, so it has broad application prospect. Recent development on catalytic pyrolysis catalysts and technologies are reviewed in this paper, the similarities and differences of various kinds of catalysts are compared, notable processes in home and abroad are introduced, and three kinds of reaction mechanisms about catalytic pyrolysis are summarized for different types of catalysts and technologies. Owing to the shortage in supply and the inferior quality of China's crude oil, the study and development of catalytic pyrolysis techniques are crucial to China. Deep Catalytic Cracking, Catalytic Pyrolysis Process and Heavy-Oil Contact Cracking are introduced with emphasis.

This paper deals with the roof structural system using prestressed girders made of ultra-high performance concrete (UHPC). One of the aims of this study is to verify whether the option of the UHPC girders could be under certain boundary conditions competitive with the commonly used construction materials. Due to its high strength, UHPC enables the design of the structural elements with the high load bearing capacity and with smaller slenderness compared to normal strength concrete elements. The price of UHPC is currently still very high compared to the normal strength concretes or steel. Therefore, its use for the usual designed structures does not recently seem too economically attractive. The effect of material savings is nonnegligible in the case, that a self-weight of the structure forms dominant component of the total load. In addition to the high strength, UHPC has very high resistance to environmental influences. It is therefore likely, that UHPC could be advantageously applied e.g. for the roofing of industrial buildings of chemical plants with high aggressive environments, because there are high demands on the life cycle of the structure.

Concrete is the most widely used construction material because of its mouldability into any required structural form and shape due to its fluid behavior at early ages. Thorough compaction, using vibration, is normally essential for achieving workability, the required strength and durability of concrete. Inadequate compaction of concrete results in large number of voids, affecting strength and long-term durability of structures. Self-compacting concrete (SCC) provides a solution to these problems. As the name signifies, it is able to compact itself without any additional vibration or compactive effort. However, widespread applications of self-compacted concrete have been restricted due to lack of standard mix design procedure and testing methods. Self-compacted concrete is used as a special concrete in place of standard concrete due to lack of mix design procedures. It is gaining wide acceptability because no vibration is needed and noise pollution is eliminated thereby. The construction process is safer and more productive. This paper presents the performance of self-compacted concrete by using ordinary Portland cement, metakaolin (MK) as a mineral admixture and Glenium B233 as a superplasticizer. Metakaolin is produced by heating kaolin, one of the most abundant natural clay minerals, to temperatures of 700–850 °C. The performance of metakaolin in self-compacting concrete is not well documented, particularly over a wide range of grades. In particular, the effects of metakaolin as a high surface area mineral addition on the workability as well as mechanical properties of self-compacting concrete need to be fully recognized. Therefore, the present study is an effort to characterize the fresh and hardened properties of self-compacting concrete containing metakaolin. Glenium B233 is an admixture of a new generation based on modified poly carboxylic ether. It is free from chloride and is compatible with all types of cements. This experimental study demonstrates that metakaolin can be successfully used as an admixture in the preparation of self-compacting concrete (SCC). In order to prepare suitable mix proportions for different grades of metakaolin based self-compacting concrete, investigations were undertaken replacing cement with 0, 10, 15, 20, 25 and 30 % of metakaolin and with different percentages of superplasticizer (Glenium B233). As per the European guidelines for self-compacting concrete, slump flow test, V-funnel test and L-box test have been carried out on fresh properties of metakaolin based self-compacting concrete. The compressive strength, split tensile strength and flexural strength of the specimens have been analyzed for 7 and 28-days curing. In addition, finally mix proportions have been recommended for low, medium and high strength grades of metakaolin based self-compacting concrete. The fresh concrete test results revealed that by substituting different percentages of metakaolin in self-compacting concrete, satisfactory workability and rheological properties could be achieved, even though no viscosity-modifying agent was needed. In general, it seems that metakaolin can be considered as suitable replacement regarding to the economic efficiency, fresh and hardened properties of metakaolin based self-compacting concrete. The test results for acceptance characteristics of self-compacting concrete such as slump flow test, V-funnel test and L-Box test were satisfactory as per EFNARC for developed mix proportions of M60, M40 and M20 grade self-compacting concrete mixes. Further, compressive strength, tensile strength and flexural strength at the ages of 7 and 28 days were also determined and 10–15 % replacement of metakaolin can be regarded as a suitable replacement and mix proportions have been recommended for low (M20), medium (M40) and high (M60) strength grades of metakaolin based self-compacting concrete from this study.

Buildings represent one of the most significant sources of negative impacts to the natural ecosystems on which Qatar's inhabitants health and environmental quality depend. The market has identified Qatar as one of the busiest construction areas in the world (Ibrahim 2011), While rapid economic development, population growth, and construction boom are positive indicators of growth, they may also present issues related to the negative impact on the socio-environmental components of cities. Such is the case of the Gulf Cooperation Council (GCC) countries where increasing economic prosperity has led to a surge in tall building construction and a sense of competition to erect the tallest skyscrapers in the world (Mahgoub and Abarra 2012).While tall buildings are a source of national pride and cultural identity enabled by economic prosperity, they pose several challenges to integrate with the urban fabric of the city while also having a tremendous environmental impact. Tall buildings are especially massive consumers of energy (Ali and Armstrong 2008). They are the dominant elements in urban architecture due to their scale and purpose, and should be the focus of sustainable design. With large number of towers constructed and to be constructed in Al Dafna and West Bay areas of Doha, these buildings affect different aspects of the built and urban environment, i.e., city image, traffic, urban spaces and physical conform. Therefore, more architectural design strategies have to be planned well ahead in order to tackle the issues of sustainability and adaptability to climate change and to foster sustainable built environment in the state of Qatar.With Qatar slated to host a ‘zero carbon’ World Cup in 2022, Qatar Green Building Council (QGBC) has set up a group to foster green infrastructure as a national resource. Qatar is utilizing Leadership in Energy and Environmental Design (LEED) and the Global/Qatar Sustainability Assessment System (GSAS/QSAS) to this end. Furthermore, shortages in raw materials between 2013 and 2017 are expected to challenge the construction sector, as the period is expected to be the peak for the sector. Therefore, the sector will have to bridge the gap during this period by mutual agreements with the companies in Saudi Arabia and the UAE (QCB 2012).The objectives of this paper are as follows: 1- to Identify sustainability metrics for tall buildings with focus on construction materials and methods used in Qatar; 2- Explore existing literature and identify analogies in optimization consistent with design variables; 3- to examine sustainability of construction materials used in Qatar by utilizing software which is based on currently available databases to perform life cycle assessment.To meet the objectivess described above, the currently available software platforms to perform life cycle analysis of building materials were explored. A commercial software, SimaPro, which utilizes the environmental impact database Ecoinvent, was chosen for its flexibility in defining custom mix designs for concrete, as well as database information on steel and many other building materials. With SimaPro, a sustainability model for concrete and steel was developed which reflects the environmental implications of manufacture of materials in Qatar as appropriate. Quantitative results from the model for the sustainability of constituents of building materials were extracted, to form the basis of sustainability metrics in the forthcoming tall building topology optimization protocol.Furthermore, Blanco-Carrasco et al (2010) outline reduced use of Portland cement, increased use of alternate cementitious materials, and reduced water use to improve the sustainability of the concrete industry in Qatar. Using structural models and the SimaPro model, ultra-high performance concrete was explored as a potential solution for all these problems, to be applied in the gravity/lateral structural components of Qatar tall buildings. In addition to identifying a novel material which fits well with the current tall building designs of the region, the process of examining the structural and environmental improvements from using ultra-high performance concrete has resulted in the formation of a procedure to compare multiple materials used in Qatar.This paper is a result of a funded research project by QNRF, entitled “Multi–Objective Tall Building Topologies – Optimizing for Structural Performance, Economy, and Sustainability” and a jointly collaboration between researchers from Qatar University, Virginia Tech, Johns Hopkins University, Optim Design Inc, and MZ & Partners.“This research/publication was made possible by a National Priority Research Program NPRP award [NPRP- 7 - 1518 - 2 – 549] from the Qatar National Research Fund (a member of The Qatar Foundation). The statements made herein are solely the responsibility of the author(s).”

Objective: The aim of this research was to quantify the CO2 emissions generated by construction materials (steel, used as reinforcement in reinforced concrete structures, sand, gravel, cement and ceramic bricks) for the construction of a veterinary hospital located in Juazeiro do Norte – CE. Theoretical framework: In Juazeiro do Norte, a city marked by strong urban expansion, the production and use of materials such as steel, sand, gravel, cement and ceramic bricks generate significant greenhouse gas emissions. Due to its industrial processes, such as the burning of fossil fuels, the calcination of limestone to produce clinker and the extraction and transportation of aggregates, these materials directly contribute to the increase in atmospheric emissions. Although Life Cycle Assessment (LCA) is the most comprehensive method for assessing environmental impacts, its complexity and cost encourage the use of alternative approaches, such as Energy Life Cycle Assessment (ELCA) and the QE-CO₂ Method, which allows the quantification of CO₂ emissions in a simplified and reliable way. Method: Quantification was performed using the QE-CO2 Method (Method for Quantifying Carbon Dioxide Emissions), developed by Costa (2012). Results and discussion: According to the results obtained in this research, using such materials in the construction under study resulted in the emission of 1,878.75 tons of CO2 into the atmosphere. The material that contributed most to CO2 emissions was cement, with 710.76 tons of CO2 emitted. Research implications: The results of this research highlight the relevance of quantifying carbon dioxide (CO₂) emissions associated with construction materials in medium-sized projects, such as the construction of a veterinary hospital. By applying the QE-CO₂ Method, it was possible to accurately identify the main inputs responsible for the emissions, highlighting cement as the largest emitter of this gas. This is important for supporting policies to mitigate environmental impacts, both in the planning and execution of construction projects. Originality/value: It lies in the practical application of the QE-CO₂ Method in a specific project located in the Cariri region of Ceará, specifically in Juazeiro do Norte, filling an important gap by highlighting the environmental impact of civil works outside large urban centers. Furthermore, the research assumes strategic value by offering data that can be used as a comparative basis for other buildings and as a reference for future life cycle assessments of materials in the civil construction sector.

In this study, the effect of firing temperature on clay bricks and cubic concrete specimens was studied at a temperature of 600 °C to investigate how these common used construction materials behave during the fire disasters. Extensive tests programs are conducted on bricks specimens that were collected from many different sites in Wait governorate as well as many groups of concrete cubic specimens at 7 and 28 day. The changing of the compressive strength of concrete and clay bricks after firing at high temperature was investigated experimentally. As well as, study the effect of firing temperature on clay bricks using efflorescence and water absorption tests on bricks. The study ascertained that the firing temperature has a significant effect on clay bricks and concrete, where they are less efficient in the load resistance capacity under compression. Also, increase in the efflorescence of bricks and decreases in average of water absorption by bricks are noticed.

Since ancient times naturally available materials are being used for the purpose of construction. Due to overutilization of these resources leads to its unavailability or depletion of these materials. On the other hand, lots of industrial wastes, municipal solid wastes are generated which are sent to landfill. The produced industrial and municipal wastes are not disposed properly. If they are not disposed safely or properly it will pose threats to the human community and also to the environment. These wastes need to be managed properly for safe disposal or alternate ways need to be identified for its utilization. This paper reviews the various types of waste that are used in construction and their usage as building material, its various application and the extent they can be used in building materials are discussed. Sugarcane bagasse ash, municipal solid waste incinerator ash, paper pulp, ground granulated blast furnace slag, copper slag are the wastes reviewed in this study. Many past researches have been identified for utilizing these industrial wastes sustainably in construction sector for manufacturing of bricks, concrete, special concrete etc. The general conclusion from the studies were that GGBS is a good alternative pozzolanic material for cement while the copper slag can be used in many forms as a replacement material in concrete. The MSWI ash is most suitable for use in cement and clay bricks whereas the sugarcane bagasse ash can be ideally used both in cement and clay bricks.

Use of sugar cane bagasse ash in ultra-high performance concrete (UHPC) as cement replacement

Ultra-High Performance Concrete (UHPC) has emerged as a leading construction material across diverse engineering applications due to its exceptional mechanical properties and durability that exceed those of conventional concrete. This comprehensive review explores UHPC’s material composition, production additives, behavior in both fresh and hardened states, and environmental durability characteristics. The low water-to-cement ratio combined with a high binder content and the use of superplasticizers result in a densely compacted microstructure, substantially enhancing UHPC’s strength. Pozzolanic additives—including silica fume (SF), metakaolin (MK), fly ash (FA), and ground granulated blast furnace slag (GGBFS)—contribute to reduced cement consumption while improving long-term durability by enhancing permeability resistance, sulfate attack mitigation, and chloride ion durability. The integration of nanomaterials such as nano-silica (NS), carbon nanotubes (CNT), and graphene oxide (GO) increases the reactive surface area within the matrix, leading to a more uniform and denser microstructure. Fiber reinforcements—comprising steel, synthetic, glass, or hybrid fibers—impart ductility to UHPC, significantly boosting tensile and flexural strengths as well as energy absorption capacity, complementing its notable compressive strength. Fresh-state properties such as consistency, slump, and flowability are critical for manufacturability and application quality, with optimized mixtures delivering superior structural performance in terms of impact resistance, fatigue durability, and fracture mechanics. Additionally, UHPC demonstrates outstanding resistance to freeze-thaw cycles, sulfate and acid attacks, and chloride ingress, making it highly suitable for infrastructure exposed to aggressive environments. This review synthesizes the current understanding of UHPC’s technical advancements and multifaceted benefits, positioning it as a next-generation sustainable construction material that meets the demanding requirements of modern infrastructure.

This research focused on improving ultra high-performance concrete (UHPC) toughness through the addition of annealed plain carbon steel fibers and stainless steel fibers that both exhibit increased ductility and strain hardening compared with conventional steel fibers used for concrete reinforcement. Implementing optimized heat treatments and selecting proper alternative alloys can improve the postyield carrying capacity of UHPCs through plastic deformations, phase transformations, and fiber pullout. This research focused on the flexural response and dynamic penetration resistance of a UHPC known as Cor-Tuf with three different steel fiber types: plain carbon steel, stainless steel that can exhibit phase transformation-induced plasticity, and annealed carbon steel with reduced tensile strength but increased ductility and strain hardening. Annealed carbon steel fibers were able to reduce mass loss by 0.8 % for 5-cm-thick dynamic impact panels. By using a phase-transformable stainless steel, the ultimate flexural strength increased from 32.0 to 42.5 MPa (33 % increase) and the postimpact velocity decreased an average of 31.5 m/s for 2.5 and 5-cm-thick dynamic impact panels. Phase transformations (austenitic to martensitic) were quantified in the stainless steel fibers of postyielded UHPC specimens using a vibrating sample magnetometer. Stainless steel fibers sampled from the postyielded tensile face of a flexural beam increased from 75 to 107 emu/g. The results of the study evidence improvements in tensile properties and toughness that can be accomplished by modifying the stress versus strain response of steel fiber reinforcement and including new energy dissipation mechanisms such as phase transformation.

Ultra-high performance concrete targets against high velocity projectile impact – a-state-of-the-art review

Study of nonlinear relationships between dosage mixture design and the compressive strength of UHPC

This paper provides a comprehensive review of ultra-high-performance geopolymer concrete (UHPGPC), an innovative, eco-friendly, and cost-effective variant of ultra-high-performance concrete (UHPC), devised to meet the rising request for ultra-high-strength construction materials. Previous research papers have not thoroughly analyzed and compared the rheological, physical, durability, and microstructural properties of UHPGPC with UHPC. Similarly, review articles scarcely investigate UHPGPC's strength properties and microstructural behavior under high temperatures. This paper includes an assessment of the correlation between compressive strength, splitting tensile strength, and modulus of elasticity (MOE). The current study also compares chloride ion penetration test outcomes, elevated temperature, electrical resistivity, and porosity tests to evaluate durability. To analyze the microstructure of UHPGPC, the paper assesses results from Fourier Transform Infrared Spectroscopy (FT-IR), Thermogravimetric Analysis (TGA), Scanning Electron Microscopy (SEM), and Mercury Intrusion Porosimetry (MIP). The findings from the present paper suggest that UHPGPC effectively meets the ideal mechanical property specifications of UHPC. Compared to UHPC, UHPGPC displayed a higher ion passage propensity due to larger pores (>100 nm). Geopolymer technologies present a greener path for producing UHPC by consuming less energy and emitting reduced CO2. Introducing mineral fillers like silica fume impacts the mixture's flowability and increases its water needs. However, adding an optimal ratio of micro-silica as a partial substitute for granulated blast furnace slag further bolsters the strength characteristics of UHPGPC. The strength of UHPC can also be notably improved by adjusting the water-to-binder ratio, with specific ratios yielding considerable enhancements in compression strength. The selection of an alkaline activator plays a pivotal role in UHPC's heat resilience. Among them, a combination of potassium hydroxide and sodium silicate is the prime chemical activator for boosting strength performance, durability behavior, and microstructural attributes, particularly at temperatures beyond 600 °C. Eco-friendly Geopolymer Composites (EGCs) offer lower embodied energy and CO2 emissions than traditional composites, with certain components like polyvinyl alcohol fibers being key contributors to these emissions. Progress in self-healing materials is driving sustainability in construction through innovative techniques, such as bacterial applications and specific chemical reactions. The strength and workability of Engineered Geopolymer Composites are influenced by their fiber content, with certain fibers interacting weaker than others. On a microstructural level, UHPGPC has a relatively weaker structure than UHPC due to differences in pore size, but its durability is improved when reinforced with fibers.