Alternative Cement Research Articles

Reduction Effect of Carbon Dioxide Emissions by Alternative Cement with Wollastonite

Reduction Effect of Carbon Dioxide Emissions by Alternative Cement with Wollastonite

SUBTITUSI SAMPAH ORGANIK DAN TANAH MEDITERAN MENJADI SEMEN ALTERNATIF SELAIN SEMEN PORTLAND

The results of this study aims to save the environment, through the discovery of new alternative materials by recycling organic waste, household waste, coal waste (fly ash and bottom ash), and substitution of mediteran land and clay into organic cement that is alternative cement in addition portland cement. Test results of organic cement chemical compound using laboratory testing method refers to ASTM C-114 and SNI 15-2049-2004. An indication of resembling a portland cement chemical compound is CaO of 65.36%, SiO₂ 18.84%, AlOO₃ 6.33%, Fe₂O₃ 2.29%, SO₃ 3.64%, MgO 1.35%, C₃S 66 , 72%, C₂S 3.98%, C₃A 12.9%, and C4Af 6.97%. Test methods of physical properties include testing of baseline time and end time and normal consistency value to organic cement, this test refers to ASTM C 191-04 and C 191-08 and ASTM C 187-04. Fineness of organic cement grains that passed in the mesh 200 mesh as much as 56%, more subtle than portland cement is 52%. The solid weight of organic cement is 1200 kg/m3, lighter than portland cement which reaches 1250 kg/m3. The initial setting time for organic cement was 105 minutes, longer than portland cement at 90 minutes. For the organic cement final time at 225 minutes, it was above the end time of portland cement at 180 minutes.

Carbonation resistance of mortar produced with alternative cements

The use of alternative cements with lower CO2 emissions during production compared to ordinary Portland cement (PC) is only sustainable, if the durability and with it the service life of components and structures produced with them are not compromised. In this project, the carbonation resistance of mortars produced with calcium sulfoaluminate cement (CSA) and three different slag-based cements is studied in accelerated conditions and natural exposure. Additionally, the diffusion coefficients of oxygen ($$D_{{{\text{O}}_{2} }}$$) and carbon dioxide ($$D_{{{\text{CO}}_{2} }}$$) are measured (the latter one only on carbonated mortars) and the change in mortar porosity due to carbonation is determined. Mortar PC used as reference and mortar CSA display the lowest carbonation coefficients, both in accelerated conditions and natural exposure. The three systems based on slag display higher carbonation coefficients. After carbonation, the diffusion coefficient $$D_{{{\text{O}}_{2} }}$$ is increased for all mortars except for mortar PC, whose total porosity is decreased as well, in contrast to all other mortars. The diffusion coefficients $$D_{{{\text{O}}_{2} }}$$ and $$D_{{{\text{CO}}_{2} }}$$ show a linear relationship in the carbonated mortars.

Ceramic waste powder an alternative cement replacement – Characterization and evaluation

In a rapidly growing world population and toward meeting consumers' needs, solid waste landfills will continue receiving extensive volumes of waste. Transforming large amount of solid wastes into an alternative resource will preserve the reducing nonrenewable resources of materials; maintain the required energy and in addition will help solve environmental and exhausted landfill problems. The utilization of solid waste materials in concrete, which is a predominant construction material, has attracted numerous studies especially those that can replace cement which is a major contributor to global green-house gas emissions. Ceramic tiles industry generates ceramic waste powder during the final polishing process. Ceramic waste powder (CWP) can cause soil, water and air pollution. Using ceramic waste powder (CWP) as an alternative ingredient in concrete will have a positive environmental impact. The aim of this study was to characterize the CWP with respect to its composition, morphology and activity. Also, the study evaluated the use of CWP as an alternative ingredient partially replacing cement on the performance of fresh and hardened concrete. In this investigation, concrete mixtures incorporating CWP as cement replacement with different replacement levels (i.e., 10%, 20%, 30% and 40% by mass) were examined. Three concrete grades with different cement contents were used (i.e., 25 MPa, 50 MPa and 75 MPa). The fresh concrete workability retention of the mixtures was evaluated by measuring time to reach zero slump. Compressive strength development with age (i.e., 7, 28 and 90 days) and drying shrinkage strain at 120 days were measured. The chloride ion penetration (i.e., rapid chloride ion penetration test - RCPT) and bulk electrical resistivity were conducted to evaluate durability performance of the mixtures. The permeable pores were measured to assess the development in the concrete microstructure. Test results showed that CWP has potential to be used as an ingredient in concrete mixtures to partially replace cement. The study showed that concrete mixtures with ceramic waste powder (CWP) had variable performance of the measured properties depending on the replacement level used. In general, CWP can be used in concrete mixtures to partially replace cement and improve specific performance criteria. A performance index (PI) approach was developed in order to be able to select the suitable CWP replacement level to optimize the mixture's specific properties to achieve a desired performance criteria. In this study, the PI considered workability retention, compressive strength and durability as performance measures for selecting the most suitable CWP replacement level. The PI could be extended to include additional criteria. The use of 10% CWP replacement level was adequate for strength improvement, replacement levels between 10% and 20% could be used to improve workability retention while a level of 40% replacement was needed for durability enhancement. For more than one performance criteria the CWP replacement level varied; a 10% to 20% CWP was suitable for optimizing the workability retention and strength of the mixture. However, the use of 30% to 40% CWP would optimize the combination of all studied criteria.

Structural analysis of consolidation settlement behaviour of soil treated with alternative cementing materials for foundation purposes

Abstract The structural analysis of the application of quarry dust (QD), crushed waste ceramics (CWC), palm bunch ash (PBA), crushed waste ceramics base geopolymer cement (CWCbGPC) and palm bunch ash base geopolymer cement (PBAbGPC) in the treatment of soil has been studied. The need to encourage the use of supplementary cementing materials in construction works is of great necessity. This is because of the further damage the emission of CO2 is causing and its contribution to global warming. Laboratory experiments have been adopted to investigate the behaviour of test soil on the addition of admixtures. After the preliminary study, it was shown that the test soil was an A-7 soil according to AASHTO classification system and poorly graded soil of high clay content (GP/CH) according to the USCS. The treatment protocol was used to study the consolidation settlement (CS) of the treated test soil and results showed that the CS reduced steadily at the varied addition of the cementing additives. A more remarkable improvement was recorded with the geopolymer cements (GPC). The results equally showed that the PBAbGPC was observed to be better than the CWCbGPC in the treatment protocol. The exercise not only achieved the ridding the environment of solid wastes but showed that these waste materials could be reclaimed and synthesized into alternative cementing materials to replace ordinary Portland cement and remove its attendant CO2 emission and the global warming effects from the atmosphere.

Characteristic of compressive and tensile strength using the organic cement compare with portland cement

The waste problem is a problem faced throughout the world. This research aims to save the environment with on the utilization of recycling waste materials that do not contribute much in people's lives over the years. Organic cement is an alternative cement besides portland cement made from organic waste recyled and substitution of mediteran soil. The research is oriented to chemical compounds, compressive strength, and tensile strength testings of concrete by using organic and portland cements. Age of concrete in the research are 3, 4, 14, 21, and 28 days old. Result for compressive test of cylinder concrete with organic cement, it obtained 6.10 MPa while the cylincer concrete with portland cement, it obtained 20.22 MPa. For tensile strength test of cylinder concrete with organic cement on 28-days-old concrete reached 1.09 MPa and those with portland cement reached 2.01 MPa. From the physical test result, it obtained the density of organic cement is 3.01 g/ml, while for the density of portland cement is 3.16 g/ml. From the analysis of organic cement chemical compounds through laboratory testing methods result, it found indications that resemble portland cement chemical compounds that are CaO;65,36%, SiO₂; 18,84%, Al₂O₃; 6,33%, Fe₂O₃; 2,29%, SO₃ ; 3,64%, MgO; 1,35%, C₃S; 66,72%, C₂S; 3,98%, C₃A; 12,9%, and C4Af; 6,97%.

The Enhancing Cement Strength through Utilization of Rice Husk Ash (RHA) Additive: An Experimental Study

Designing a slurry with adequate strength resistance is a major objective in oil and gas completion job. Various studies and research confirms that Compressive Strength (CS) and Shear Bond Strength (SBS) are two parameter which is imperative in describing cement strength in well cementing job. This experimental study introduces a Rice Husk Ash (RHA), an alternative cement additive derived from organic waste. RHA rich in silicon oxide (SiO2) and has a pozzolanic reaction, which is correlated in enhancing cement strength. Serial cement samples with various concentration of RHA were prepared to investigate the effect of RHA concentration to CS and SBS. All samples were then Dried for 24 hours in room condition after completing mixing and molding process. A Biaxial Loading test was then performed to all samples to determine the CS and SBS values by using hydraulic press apparatus. Results from the loading test generally indicate an enhancement of CS and SBS for samples with 31%, 32%, 33%, and 34% RHA. An indication of higher CS and SBS is not found for sample with 35% RHA, comparing with 34% RHA. Thus, 34% RHA is the optimum concentration for theses study, which yield 1312. psi of CS and 158.16 psi of SBS. Through this study, there is an opportunity for transforming waste material into alternative additive with higher economic value. 
 

Development of Geopolymer Mortar from Metakaolin Blended with Agricultural and Industrial Wastes

Geopolymer is a greener alternative cement produced from the reaction of pozzolans and strong alkali solutions. Generally, the cement industry is one of largest producers of CO2that caused global warming. For geopolymer mortar usage, Portland cement is not utilized at all. In this research, geopolymer mortars were prepared by mixing metakaolin, various wastes (fly ash, bagasse ash and rice husk ash) varied as 80:20, 50:50 and 20:80, 15M NaOH, Na2SiO3and sand. The influence of various parameters such as metakaolin to ashes ratios and pozzolans to alkali ratios on engineering properties of metakaolin blended wastes geopolymer mortar were studied. Compressive strength tests were carried out on 25 x 25 x 25 mm3cube geopolymer mortar specimens at 7, 14, 21, 28 and 91 air curing days. Physical and chemical properties were also investigated at the same times. The test results revealed that the highest compressive strength was 20% metakaolin - 80% fly ash geopolymer mortar. When the curing times increases, the compressive strength of geopolymer mortar also increases. The mixing of metakaolin and bagasse ash/rice husk ash presented lower compressive strength but higher water absorption and porosity. For FTIR results, Si-O, Al-O and Si-O-Na+were found. Moreover, the geopolymer mortar could easily plastered on the wall.

Effects of composition and transportation logistics on environmental, energy and cost metrics for the production of alternative cementitious binders

Abstract The production of cement, the primary ingredient in concrete, is responsible for 5–10% of anthropogenic GHG emissions. Numerous studies have investigated ordinary portland cement (OPC) alternatives with the goal of reducing GHG emissions. This life cycle assessment (LCA) adds transportation as a focus of the assessment, in addition to the process steps from cradle to the gate of finished cementitious product. GHG emissions and cost are assessed for five cement types with comparable performance (1) OPC; (2) blended OPC with slag (SC); (3) blended OPC with fly ash (FAC); (4) metakaolin-based geopolymer (MKG); and (5) high volume limestone alkali-activated slag cements (HLAASCs). Transportation logistics are known to be critical for the cement industry, and this holds true for alternative cements. The influence of feedstock source location and transport mode within the supply chain significantly affect both environmental impacts (up to 80% of GHG emissions) and production cost (up to 65%), and should thus be a major consideration. All OPC alternatives reduce GHG emissions, even at the least beneficial points of their ranges. HLAASC reduces GHG emissions and energy consumption in all cases studied, by up to 95% and 83%. SC and FAC have comparable reductions in GHG emissions and energy, and their ranges overlap. MKG reduces GHG emissions but not energy input for the cases studied, however the energy demand may be closer to the other binders studied where the mineral is available and from low grade sources.

KUALITAS SEMEN CAIR SAPI SIMENTAL MENGGUNAKAN LARUTAN ISOTONIS KOMERSIAL PADA KONSENTRASI DAN LAMA PENYIMPANAN BERBEDA

Artificial insemination (AI) is a technique to insert the sperm or semen of bull thawed and processed first into the genital tract of female methods and a special tool called insemination gun, efforts to optimize the management of the cement in order to obtain the quality of cement is optimal to do with the selection of diluent cement. One alternative materials cement diluent is an isotonic solution Commercial (LIK). This study aimed to examine the interaction between the concentration and duration of storage of diluent solution isotonic different to the quality of spermatozoa cow simental. This research was conducted at the Regional Technical Implementation Unit of Artificial Insemination Centres (UPTD BIB) Tuah Sakato, Payakumbuh. In April 2016. This study used a randomized block design (RAK) factorial design to Factor A (Concentration LIK) ie A1 = 100 ml Tris Egg Yolk, A2 = (60 ml) Tris Egg Yolk + (40 ml) LIK, A3 = (55 ml) Tris Egg Yolk + (45 ml) LIK, A4 = (50 ml) Tris Egg Yolk + (50 ml) LIK, and factor B (retention) is B1 = 0 day, B2 = 1, B3 = 2 day, days, B4 = 3 days. Each treatment consists of three replicates. Parameters measured were motility, percentage of survival, abrnormalitas, and MPU. These results indicate that an isotonic solution can be used as an alternative Commercial diluent with the best results on the percentage LIK 40 ml, but the effectiveness of the efficiency of storage use was only on the first day (24 hours).

Synchrotron Radiation Pair Distribution Function Analysis of Gels in Cements

The analysis of atomic ordering in a nanocrystalline phase with small particle sizes, below 5 nm, is intrinsically complicated because of the lack of long-range order. Furthermore, the presence of additional crystalline phase(s) may exacerbate the problem, as is the case in cement pastes. Here, we use the synchrotron pair distribution function (PDF) chiefly to characterize the local atomic order of the nanocrystalline phases, gels, in cement pastes. We have used a multi r-range analysis approach, where the ~4–7 nm r-range allows determining the crystalline phase contents; the ~1–2.5 nm r-range is used to characterize the atomic ordering in the nanocrystalline component; and the ~0.2–1.0 nm r-range gives insights about additional amorphous components. Specifically, we have prepared four alite pastes with variable water contents, and the analyses showed that a defective tobermorite, Ca11Si9O28(OH)2.8.5H2O, gave the best fit. Furthermore, the PDF analyses suggest that the calcium silicate hydrate gel is composed of this tobermorite and amorphous calcium hydroxide. Finally, this approach has been used to study alternative cements. The hydration of monocalcium aluminate and ye’elimite pastes yield aluminum hydroxide gels. PDF analyses show that these gels are constituted of nanocrystalline gibbsite, and the particle size can be as small as 2.5 nm.

Polymer-Cement Composites with Self-Healing Ability for Geothermal and Fossil Energy Applications

Sealing of wellbores in geothermal and tight oil/gas reservoirs by filling the annulus with cement is a well-established practice. Failure of the cement as a result of physical and/or chemical stress is a common problem with serious environmental and financial consequences. Numerous alternative cement blends have been proposed for the oil and gas industry. Most of these possess poor mechanical properties, or are not designed to work in high temperature environments. This work reports on a novel polymer-cement composite with remarkable self-healing ability that maintains the required properties of typical wellbore cements and may be stable at most geothermal temperatures. We combine for the first time experimental analysis of physical and chemical properties with density functional theory simulations to evaluate cement performance. The thermal stability and mechanical strength are attributed to the formation of a number of chemical interactions between the polymer and cement matrix including covalent bonds...

Evaluarea liantilor geopolimerici activati alcalin ca alternativa la cimentul Portland

This study summarizes the recent achievements in the development of alternative cement free binder materials (cementless) called alkali activated binder or more popularly known as geopolymers. The history of the development of alkali activated binder and recent terminology are discussed. The influence of the type of the base materials on the properties of goepolymers are thoroughly reviewed. The effect of composition and concentration of alkali and curing temperature on the properties and mechanical behavior of the resulting alkali activated material are discussed. Different type of base materials used in the formation of alkali activated material are blast furnace slag, metakaolin, fly ash, bottom ash, volcanic ashes, and red mud. The state-of-the art in this field demonstrated that this type of materials are ecologically friendly alternative of the Ordinary Portland cement.

Impact of the selection of functional unit on the life cycle assessment of green concrete

Purpose The objectives of this study are to evaluate life cycle assessment (LCA) for concrete mix designs containing alternative cement replacement materials in comparison with conventional 100% general use cement concrete and to evaluate the interplay and sensitivity of LCA for four concrete mix designs and six functional units which range in degrees of complexity and variables.

The Performance of the Low Cost Masonry Cement Blocks as a Partial Substitution of Coconut Shell Ash

Aim of the research was to investigate the effect of Coconut Shell Ash (CSA) with cement as a partial substitution in the production of alternative cement blocks to subsist conventional ones. Utilization of this natural agro waste material helps to prevent the environmental pollution, reduces the construction cost as well as contributes to sustainable construction. Therefore, 90 blocks of 450 mm × 150 mm × 225 mm masonry cement blocks of mixing value 1:6 were cast, cured and tested after 7, 21 and 28 days. CSA was substituted at 0 to 50 wt.% at 5% intervals. The materials were mixed well with the addition of sufficient water. The maximum compressive strength and flexural strength of 300 kg/cm2 and 12.52 kg/cm2 were recorded at 5% supersession at the 28th day, respectively, which is found congruous and recommended for building construction having procured a 28th day compressive strength of more than 280 kg/cm2 as required by the Sri Lankan Standards. The compressive and flexural strengths of the cement / CSA blocks generally decrease as the percentage of CSA content increases. However the dry density, water absorption, compressive strength and flexural strength results conclude that the 10% CSA addition is the optimal value for the production of environmental friendly low cost alternative cement blocks.

Alternative cements based on alkali-activated red clay brick waste

The synthesis of alkali-activated and hybrid cements based on red clay brick waste was investigated using sodium hydroxide and sodium silicate solution as alkaline activators. The effect on the compressive strength of Na2O/SiO2 and SiO2/Al2O3 molar ratios and type of curing was evaluated. The combined presence of Portland cement (20%) and sodium silicate yielded a maximum compressive strength of 102.6MPa at 28 days and 25°C; this value is two times higher than the strength obtained in mixtures without Portland cement and 7.3 times higher than when sodium hydroxide is used. The results demonstrated the feasibility of using these materials to produce structural and non-structural construction elements.

Micrographical, minerological and nano-mechanical characterisation of microbial carbonates from urease and carbonic anhydrase producing bacteria

Microbial carbonates are emerging as sustainable alternative cementing materials. We explore carbonate mineralisation by three bacterial isolates: Sporosarcina pasteurii, Bacillus pumilis and Bacillus megaterium that produce two enzymes urease and carbonic anhydrase. In vitro CaCO3 precipitation by bacterial isolates under three different energy sources: urea, NaHCO3 and CO2 was monitored quantitatively and qualitatively. Cell viability in different treatments was studied through fluorescent microscopy. Morphological and chemical constituents of the crystals formed by different bacterial isolates were analysed by scanning electron microscopy, X-ray diffraction and Energy dispersive X-ray spectrum. In a first attempt we estimate the mechanical properties of microbial products through nanoindentation and correlate them with the established techniques such as SEM and XRD. The biochemical processes produced a mixture of two forms of carbonate, calcite and vaterite, in different proportions. We demonstrate that it is possible to engineer the mechanical properties of the carbonates by controlling the biochemical processes.

Use of non-wood biomass combustion ash in development of alkali-activated concrete

The work reported herein focuses on demonstrating the value of non-wood biomass combustion ash in production of alkali-activated concrete. The growing use of biomass as fuel leaves significant quantities of solid residue (ash) with qualities that are different from those of coal combustion ash. The composition of biomass ash suits development of alternative cement chemistries with significantly reduced carbon footprint and energy content when compared with Portland cement. Sustainable cement chemistries relying upon alkali aluminosilicate hydrate as the primary binder are receiving growing attention. Combustion ashes of wheat straw, switch grass, corn cob, alfalfa stem, corn stalk, cotton gin and rice hull were evaluated in this investigation. Characterization of the chemical composition, mineralogy, degree of crystallinity, solubility, pH in solution, loss on ignition, morphology and particle size distribution of non-wood biomass ashes, and the strength and moisture stability of the resulting concrete provided a basis for assessment of the merits of non-wood biomass ash as reactive raw materials in production of alkali-activated concrete.

Recent update on the environmental impact of geopolymers

The contribution of building materials’ production to environmental impacts becomes significant in the new energy efficient buildings that are currently built. Among those materials, cement represents a major part of the embodied carbon footprint of buildings. Development of alternatives to traditional Portland cement have emerged over the last decades; however, their environmental assessment over their life cycle have resulted in conflicting results, which give a confusing picture of the strategic path to be followed. This paper focuses on the alkali-activated cement and concrete and points out the variability linked with the choice of energy source for the production of the activators and precursors. A review of existing studies is then performed in order to highlight the main benefits of these alternative cements in terms of reduction of greenhouse gas emissions. Finally, the results presented here highlight further research trends for new cements and concrete.

Recent update on the environmental impact of geopolymers

The contribution of building materials’ production to environmental impacts becomes significant in the new energy efficient buildings that are currently built. Among those materials, cement represents a major part of the embodied carbon footprint of buildings. Development of alternatives to traditional Portland cement have emerged over the last decades; however, their environmental assessment over their life cycle have resulted in conflicting results, which give a confusing picture of the strategic path to be followed. This paper focuses on the alkali-activated cement and concrete and points out the variability linked with the choice of energy source for the production of the activators and precursors. A review of existing studies is then performed in order to highlight the main benefits of these alternative cements in terms of reduction of greenhouse gas emissions. Finally, the results presented here highlight further research trends for new cements and concrete.