Use of calcium carbonate nanoparticles in production of nano-engineered foamed concrete

Researchers have shown significant interest in the incorporation of nanoscale components into concrete, primarily driven by the unique properties exhibited by these nanoelements. A nanoparticle comprises numerous atoms arranged in a cluster ranging from 10 nm to 100 nm in size. The brittleness of foamed concrete (FC) can be effectively mitigated by incorporating nanoparticles, thereby improving its overall properties. The objective of this investigation is to analyze the effects of incorporating calcium carbonate nanoparticles (CCNPs) into FC on its mechanical and durability properties. FC had a 750 kg/m3 density, which was achieved using a binder-filler ratio of 1:1.5 and a water-to-binder ratio of 0.45. The CCNPs material exhibited a purity level of 99.5% and possessed a fixed grain size of 40 nm. A total of seven mixes were prepared, incorporating CCNPs in FC mixes at the specific weight fractions of 0% (control), 1%, 2%, 3%, 4%, 5%, and 6%. The properties that were assessed included the slump, bulk density, flexural strength, splitting tensile strength, compressive strength, permeable porosity, water absorption, drying shrinkage, softening coefficient, and microstructural characterization. The results suggested that incorporating CCNPs into FC enhanced its mechanical and durability properties, with the most optimal improvement observed at the CCNPs addition of 4%. In comparison to the control specimen, it was witnessed that specimens containing 4% CCNPs demonstrated remarkably higher capacities in the compressive, splitting tensile, and flexural tests, with the increases of 66%, 52%, and 59%, respectively. The addition of CCNPs resulted in an improvement in the FC porosity and water absorption. However, it also led to a decrease in the workability of the mixtures. Furthermore, the study provided the correlations between the compressive strength and splitting tensile strength, as well as the correlations between the compressive strength and flexural strength. In addition, an artificial neural network approach was employed, utilizing k-fold cross-validation, to predict the compressive strength. The confirmation of the property enhancement was made through the utilization of a scanning electron microscope

Overview on properties of sugarcane bagasse ash (SCBA) as Pozzolan

1934-1945This review paper will explore the detailed information on the Sugar Cane Bagasse Ash (SCBA) historical experimental studies, morphological aspects, chemical and physical properties of SCBA along with some fresh and hardened SCBA blended concrete properties. Importance of this overview is to understand the variation of SCBA properties with respect to geological variation, sugarcane cultivation methods and production of ashes methods. Based on the SCBA test properties, the characterization of SCBA at different parts of the world are reviewed and recommendations are suggested that it can be used as pozzolan suitable for marine environment construction

Identification of groundwater potential zones using remote sensing and GIS techniques, in Muguru Addahalla watershed, Mysore and Chamarajnagar districts, Karnataka, India

Groundwater recharge from surface water sources is an essential aspect in any watershed or a hydrological unit. For any small scale groundwater assessment, experimental approaches are usually adopted. However, recharge into aquifers depends on several hydrogeological factors on a regional scale analysis; groundwater assessment is conducted in a comprehensive approach considering all the geospatial data of different contributing factors. These factors include geomorphological, geological and structural elements like lineaments, drainage frequency, drainage density, lithology, land use and land cover. This study has been conducted with an integrated approach to identify the groundwater potential of the area, and the factors influencing groundwater recharge. The study has shown that the prevailing groundwater conditions are very good along the stream networks and the remaining zones show moderate to poor groundwater resources. It is also found that for such an integrated study, the tools and techniques of remote sensing and GIS are more useful

Effect of processed sugarcane bagasse ash on compressive strength of blended mortar and assessments using statistical modelling

There is much agriculture and non-agricultural waste that contains pozzolanic material, which can be recommended to use as a partial replacement for Ordinary Portland Cement (OPC). One of the waste products from sugar industries, which possess pozzolanic properties, is Sugar Cane Bagasse Ash (SCBA). Because of the negative impact associated with cement production, OPC is being replaced by several supplementary cementitious materials / pozzolanic materials. In the current study, an effort has been made to use the SCBA by partially replacing the OPC for mortar studies. SCBA has been processed to enhance the chemical and physical properties. OPC is partially replaced by Processed Sugar Cane Bagasse Ash (PSCBA) up to 30% by a 5% increment. PSCBA blended cement mortar contains different proportions of PSCBA blended cement: river sand as 1:3, 1:4, and 1:5 with different water-to-binder (W/B) ratios based on the flow studies. Experimental research was done to determine the effects of the W/B ratio, river sand, and PSCBA on the formation of the cube compressive strength of PSCBA blended cement mortar for curing times of 7, 14, 28, 56, and 112 days. An increase in compressive strength about 6.4%, 9.3%, and 8.2% for 1:3, 1:4 and 1:5 with different W/B ratios for 28 days is reported. Based on the investigational results, the coefficients of strength for various relationships proposed by different researchers have been calculated for the binder: sand ratio as 1:3 and 28 days curing period. Various relationships, including Abraham, Feret, Singh, and Bolomey law are used to validate the mixes of the PSCBA blended cement for different water-to-binder ratios and different curing periods. A novel relation has been developed through the extension of studies to forecast the compressive strength of PSCBA blended mortar mixes with various W/B ratios for various curing times

Altering Natural Ecosystems Causes Negative Consequences on the Soil Physical Qualities: An Evidence-Based Study from Nilgiri Hill Region of Western Ghats, India

Land use change (LUC) has direct and indirect consequences on soil quality. To gain insight into how LUC influences the physical properties of soil, it can be advantageous to compare undisturbed ecosystems with those that have naturally evolved over time, as well as to use soil quality indices to pinpoint the sensitivity of each ecosystem and land use change (LUC). A soil survey was carried out in the six major ecosystems of the Nilgiri Hill Region: cropland (CL), deciduous forest (DF), evergreen forest (EF), forest plantation (FP), scrubland (SL), and tea plantation (TP), with those having an establishment for over 50 years being selected and analyzed for soil physical parameters. In addition, soil quality indices were also derived to pinpoint the vulnerability of each ecosystem to LUC. The results reveal that the changes in land use significantly altered the soil physical properties. The content of clay was higher in EF and DF and increased with the soil profile’s depth, whereas the sand content was higher in CL and TP and decreased with the depth increment. BD and PD were significantly lower in EF, DF, SL, and FP, whereas they were higher in CL and TP. PS and ASM followed a similar trend to BD and PD. Owing to undisturbed natural settings, an abundance of litter input, and higher carbon concentrations, the HC was higher in EF, DF, SL, and FP, whereas, in the case of anthropogenic-influenced ecosystems such as CL and TP, it was lower. We discovered that LUC has altered Ag S, WSA, and MWD. Due to tillage and other cultural practices, Ag S, WSA, and MWD were significantly lower in CL and TP. However, the results confirm that native ecosystems (EF and DF) with a higher carbon content prevent such degradation, thereby resulting in good Ag S, WSA, and MWD.Validerad;2023;Nivå 2;2023-11-13 (joosat);Funder: Department of Science and Technology, Government of India (IF190855); King Saud University, Riyadh, Saudi Arabia, (RSPD2023R958)License fulltext: CC BYPart of special issue: Soil Legacies, Land Use Change and Forest and Grassland Restoration</p

The Present State of the Use of Waste Wood Ash as an Eco-Efficient Construction Material: A Review

A main global challenge is finding an alternative material for cement, which is a major source of pollution to the environment because it emits greenhouse gases. Investigators play a significant role in global waste disposal by developing appropriate methods for its effective utilization. Geopolymers are one of the best options for reusing all industrial wastes containing aluminosilicate and the best alternative materials for concrete applications. Waste wood ash (WWA) is used with other waste materials in geopolymer production and is found in pulp and paper, wood-burning industrial facilities, and wood-fired plants. On the other hand, the WWA manufacturing industry necessitates the acquisition of large tracts of land in rural areas, while some industries use incinerators to burn wood waste, which contributes to air pollution, a significant environmental problem. This review paper offers a comprehensive review of the current utilization of WWA with the partial replacement with other mineral materials, such as fly ash, as a base for geopolymer concrete and mortar production. A review of the usage of waste wood ash in the construction sector is offered, and development tendencies are assessed about mechanical, durability, and microstructural characteristics. The impacts of waste wood ash as a pozzolanic base for eco-concreting usages are summarized. According to the findings, incorporating WWA into concrete is useful to sustainable progress and waste reduction as the WWA mostly behaves as a filler in filling action and moderate amounts of WWA offer a fairly higher compressive strength to concrete. A detail study on the source of WWA on concrete mineralogy and properties must be performed to fill the potential research gap

Comparative mapping of DNA markers from the familial Alzheimer disease and Down syndrome regions of human chromosome 21 to mouse chromosomes 16 and 17.

Mouse trisomy 16 has been proposed as an animal model of Down syndrome (DS), since this chromosome contains homologues of several loci from the q22 band of human chromosome 21. The recent mapping of the defect causing familial Alzheimer disease (FAD) and the locus encoding the Alzheimer amyloid beta precursor protein (APP) to human chromosome 21 has prompted a more detailed examination of the extent of conservation of this linkage group between the two species. Using anonymous DNA probes and cloned genes from human chromosome 21 in a combination of recombinant inbred and interspecific mouse backcross analyses, we have established that the linkage group shared by mouse chromosome 16 includes not only the critical DS region of human chromosome 21 but also the APP gene and FAD-linked markers. Extending from the anonymous DNA locus D21S52 to ETS2, the linkage map of six loci spans 39% recombination in man but only 6.4% recombination in the mouse. A break in synteny occurs distal to ETS2, with the homologue of the human marker D21S56 mapping to mouse chromosome 17. Conservation of the linkage relationships of markers in the FAD region suggests that the murine homologue of the FAD locus probably maps to chromosome 16 and that detailed comparison of the corresponding region in both species could facilitate identification of the primary defect in this disorder. The break in synteny between the terminal portion of human chromosome 21 and mouse chromosome 16 indicates, however, that mouse trisomy 16 may not represent a complete model of DS