A Review on Mechanical Properties of Sustainable Concrete by using Rise husk ash and hydrated lime

Concrete is a commonly used construction material all over the globe. Environmentally conscious construction is essential in today’s society. By using the proper materials, we may achieve long-term construction. RHA is often used as a cementitious product replacement, and in such cases, we may mix RHA with hydrated lime. Many research has been conducted on RHA, and they all indicate that it outperforms other kinds of concrete. The importance of rice husk ash in construction and its applications are the subject of this essay. Many studies have been undertaken to identify appropriate replacements for cement in concrete mixes to reduce our over-reliance on cement as a component in concrete production owing to its contribution to CO2 emissions. This article examined the research on the usage of fly ash and rice husk ash as partial concrete replacements and the chemical composition of these materials, and their impact on concrete compressive strength. The mix was created using a logical approach in which solid components were set, and water and superplasticizer content were modified to get the best viscosity and flowability. Rice husk ash (RHA) is a rice milling byproduct. Its usage as a soil stabilizer provides an environmentally friendly alternative to ultimate disposal. Because RHA is not self-cementitious, a hydraulic binder, such as lime, must be added to create cement types to strengthen the soil. In sandy soils, studies on stabilization using RHA and lime mixtures were carried out. RHA of rice husk incineration in ordinary ovens with no temperature control and laboratory burning at regulated temperatures were utilized. In soil mixes with varying RHA and lime concentrations, cementitious compounds were found to develop. Soils treated with RHA and lime underwent unconfined compression strength testing. All RHA and lime concentrations and periods tested showed strength gains, and all materials created were changed rather than stabilized. The use of RHA to improve sandy soils offers environmental, social, and economic advantages as an alternative to ultimate disposal.

A Review on Mechanical Properties of Sustainable Concrete by using Rise husk ash and hydrated lime

Concrete is a commonly used construction material all over the globe. Environmentally conscious construction is essential in today's society. By using the proper materials, we may achieve long-term construction. RHA is often used as a cementitious product replacement, and in such cases, we may mix RHA with hydrated lime. Many research has been conducted on RHA, and they all indicate that it outperforms other kinds of concrete. The importance of rice husk ash in construction and its applications are the subject of this essay. Many studies have been undertaken to identify appropriate replacements for cement in concrete mixes to reduce our over-reliance on cement as a component in concrete production owing to its contribution to CO2 emissions. This article examined the research on the usage of fly ash and rice husk ash as partial concrete replacements and the chemical composition of these materials, and their impact on concrete compressive strength. The mix was created using a logical approach in which solid components were set, and water and superplasticizer content were modified to get the best viscosity and flowability. Rice husk ash (RHA) is a rice milling byproduct. Its usage as a soil stabilizer provides an environmentally friendly alternative to ultimate disposal. Because RHA is not self-cementitious, a hydraulic binder, such as lime, must be added to create cement types to strengthen the soil. In sandy soils, studies on stabilization using RHA and lime mixtures were carried out. RHA of rice husk incineration in ordinary ovens with no temperature control and laboratory burning at regulated temperatures were utilized. In soil mixes with varying RHA and lime concentrations, cementitious compounds were found to develop. Soils treated with RHA and lime underwent unconfined compression strength testing. All RHA and lime concentrations and periods tested showed strength gains, and all materials created were changed rather than stabilized. The use of RHA to improve sandy soils offers environmental, social, and economic advantages as an alternative to ultimate disposal

Endless November? Citizen Beliefs Concerning Wood As A Construction Material Under Extreme Weather Events

Climate change places great pressure on the construction sector to decrease its greenhouse gas emissions and to create solutions that perform well in changing weather conditions. In the urbanizing world, wood construction has been identified as one of the opportunities for mitigating these emissions. Our study explores citizen opinions on wood usage as a building material under expected mitigation and adaptation measures aimed at a changing climate and extreme weather events. The data are founded on an internet-based survey material collected from a consumer panel from Finland and Sweden during May–June 2021, with a total of 2015 responses. By employing exploratory factor analysis, we identified similar belief structures for the two countries, consisting of both positive and negative views on wood construction. In linear regressions for predicting these opinions, the perceived seriousness of climate change was found to increase positive views on wood construction but was insignificant for negative views. Both in Finland and Sweden, higher familiarity with wooden multistory construction was found to connect with more positive opinions on the potential of wood in building, e.g., due to carbon storage properties and material attributes. Our findings underline the potential of wood material use as one avenue of climate change adaptation in the built environment. Future research should study how citizens’ concerns for extreme weather events affect their future material preferences in their everyday living environments, also beyond the Nordic region.

Few-Layers Graphene-Based Cement Mortars: Production Process and Mechanical Properties

Cement is the most-used construction material worldwide. Research for sustainable cement production has focused on including nanomaterials as additives to enhance cement performance (strength and durability) in recent decades. In this concern, graphene is considered one of the most promising additives for cement composites. Here, we propose a novel technique for producing few-layer graphene (FLG) that can fulfil the material demand for the construction industry. We produced specimens with different FLG loadings (from 0.05% to 1% by weight of cement) and curing processes (water and saturated air). The addition of FLG at 0.10% by weight of cement improved the flexural strength by 24% compared to the reference (bare) sample. Similarly, a 0.15% FLG loading by weight of cement led to an improvement in compressive strength of 29% compared to the reference specimen. The FLG flakes produced by our proposed methodology can open the door to their full exploitation in several cement mortar applications, such as cementitious composites with high durability, mechanical performance and high electrical conductivity for electrothermal applications.

The Ecological Significance of Aphid Cornicles and Their Secretions

Aphid cornicles are abdominal appendages that secrete an array of volatile and nonvolatile compounds with diverse ecological functions. The emission of alarm pheromones yields altruistic benefits for clone-mates in the aphid colony, which is essentially a superorganism with a collective fate. Secreted droplets also contain unsaturated triglycerides, fast-drying adhesives that can be lethal when smeared on natural enemies but more often impede their foraging efficiency. The longest cornicles have evolved in aphids that feed in exposed locations and are likely used to scent-mark colony intruders. Reduced cornicles are associated with reliance on alternative defenses, such as the secretion of protective waxes or myrmecophily. Root-feeding and gall-forming lifestyles provide protected feeding sites and are associated with an absence of cornicles. In some eusocial gall-formers, soldier morphs become repositories of cornicle secretion used to defend the gall, either as menopausal apterae that defend dispersing alatae or as sterile first instars that dispatch predators with their stylets and use cornicle secretions as a construction material for gall repair. Collectively, the evidence is consistent with an adaptive radiation of derived cornicle functions molded by the ecological lifestyle of the aphid lineage.

A striking growth of CO2 emissions from global cement industry driven by new facilities in emerging countries

Global industrialization and urbanization processes enabled a diverse cement production boom over the past three decades, as cement is the most important building construction material. Consequently, the cement industry is the second-largest industrial CO2 emitter (~25% of global industrial CO2 emissions) globally. In this study, the Global Cement Emission Database, which encompasses anthropogenic CO2 emissions of individual production units worldwide for 1990-2019, was developed. A recently developed unit-level China Cement Emission Database is then applied to override China’s data and the combination of two database is used to reveal the unit characteristics of CO2 emissions and ages for global cement plants, assess large disparities in national and regional CO2 emissions, growth rates and developmental stages from 1990-2019, and identify key emerging countries of carbon emissions and commitment. This study finds that globally, CO2 emissions from the cement industry have increased from 0.86 Gt in 1990 to 2.46 Gt in 2019 (increasing by 186%). More importantly, the large CO2 emissions and the striking growth rates from those emerging countries, including most of developing countries in Asia and the Middle East and Africa, are clearly identified. For example, the Middle East and Africa, including mostly developing or underdeveloped countries, only represented 0.07 Gt CO2 in 1990 (8.4% of the total), in contrast to 0.26 Gt (10.4% of the total) CO2 in 2019, which is a 4.5% average growth rate during 1990-2019. Further, the intensive expansion of large and new facilities since 2005 in Asia and the Middle East and Africa has resulted in heavy commitment (90.1% of global commitment in 2019), and mitigation threats in the future considering their increasing emissions (national annual growth rate can be up to >80%) and growing infrastructure construction (~50% of clinker capacity operating ≤10 years). Our results highlight the cement industry’s development and young infrastructure in emerging economies; thus, future increasing cement demand and corresponding carbon commitment would pose great challenges to future decarbonization and climate change mitigation.

Life Cycle Assessment of a Wall Made of Prefabricated Hempcrete Blocks

Hempcrete is a natural building material obtained mixing hemp shives (i.e., the woody core of the hemp plant) with a lime-based binder and water. Hempcrete as construction material is gaining increasing interest as the EU aims to achieve net zero emissions by 2050. This material has, in fact, the ability to uptake carbon dioxide from air (i.e., via carbonation) and to store carbon for long time. The goal of the present work is to deeper analyze the environmental profile of hempcrete, in order to assess its potentials in reducing emissions of construction sector. Specifically, Life Cycle Assessment (LCA) of a non-load-bearing wall made of hempcrete blocks is carried on. The analysis encompasses the whole life cycle from the extraction of raw materials to the end of the service life. The analyzed blocks are produced by an Italian company. Only aerial lime is used as binder, microorganisms are added to the blocks to accelerate carbonation. The impact on climate change is assessed through the GWP 100 method proposed by IPCC. Preliminary results reveal a nearly neutral carbon budget.

Experimental Investigation on Making of Plastic Brick

Since the building made of cement concrete consumes almost half of the total energy generated and accordingly accountable for huge amount of CO2 emission, it is necessary to replace the Portland cement (PC) with sustainable construction material. Similarly, Prosopis Juliflora is a shrub or small tree in the family Fabaceae, a kind of mesquite which is considered to be a potential threat for ground water in South India. Hence, this has to eradicate so as to maintain the groundwater and also to effectively utilize its ash thereby reducing environmental pollution, this can be used as a partial replacement for cement. In this regard, this paper investigates the technical feasibility of using Prosopis Juliflora ash (PJA) as cementitious material by partially (5%, 10% and 15%) replacing cement by Prosopis Juliflora ash. The mixes were evaluated for their fresh, physical and strength properties such as workability, density and compressive strength and the results were compared with the conventional mix. In order to save the environment and to save the resources we have come up with using the Prosopis Juliflora (Semai-Karuvelam in Tamil) ash as the partial replacement of cement. Cement will produce equal amount of greenhouse gas (co2) which increase the global warming. As the amount of cement is reduced greenhouse gases also reduced. Utilization of Juliflora ash as a partial substitution for cement is one of the promising methods to increase the strength and thermal insulation for cement blocks. The strength parameters (compressive strength, split tensile strength and flexural strength) of concrete with blended Prosopis Juliflora cement are evaluated.