Effect of Recycled Aggregate Concrete and Steel Fibers on the Strength of Self-Compacting Concrete

The accumulation of waste materials in landfills without treatment threatens public health and the environment. The quantity of solid waste continually increases, causing environmental pollution. One of these wastes that should receive scientific treatment is concrete waste. The use of concrete waste as fine or coarse aggregate in self-compacting concrete (SCC) is one of the useful solutions to this problem. This study aims to reuse concrete waste as coarse aggregate in the production of SCC and find out the influence of different steel fiber contents on the strength of SCC. The steel fibers (SF) were used to reinforce SCC in three different volumes (0, 0.5, and 1 % of concrete volume), and the recycled coarse aggregate (RCA) was used to replace natural coarse aggregate (NCA) in five replacement levels of 0, 25, 50, 75, and 100%. The compressive and tensile strengths of the SCC specimens in the hardened state were determined. The results of the experimental study refer to the steel fiber having a positive effect on the enhancement of mechanical properties, particularly the tensile strength of SCC. The addition of 50% recycled aggregates in the concrete mix contributed to increasing the compressive strength by about 20%. Therefore, it can be said that the dual use of recycled aggregates with steel fibers produced concrete with high specifications compared to ordinary concrete. Another positive effect lies in the disposal of concrete waste, which contributes to an economic return in addition to reducing the effect on the environment

Effect of Recycled Aggregate Concrete and Steel Fibers on the Fresh Properties of Self-Compacting Concrete

Globally, the amount of solid waste is constantly increasing, and its disposal is one of the critical issues in recent research studies. Concrete waste includes the rubble of demolished buildings, whether old buildings or those that have been subjected to earthquakes, etc. This research project aims to improve sustainability in the construction industry by recycling and reusing coarse aggregate that was previously used in concrete buildings. The objective is to utilize this recycled material to produce self-compacting concrete (SCC) and assess its performance in its fresh state. By finding new ways to repurpose materials that would otherwise go to waste, this research contributes to developing environmentally friendly practices and reducing the industry's carbon footprint. Furthermore, evaluating the performance of the recycled coarse aggregate in SCC will provide insights into its potential for future use in construction projects, which could ultimately lead to cost savings and improved efficiency in the industry. Recycled coarse aggregate (RCA) was used as a substitute for the natural coarse aggregate (NCA) with volume ratios of 0, 25, 50, 75, and 100%, and steel fibers (SF) were added to the concrete with different volumes ratios (0, 0.5, and 1 %). Workability tests such as slump flow, V-funnel, and L-box tests were carried out for the mixtures in their fresh state. In general, the results of the experimental work showed that the fresh properties indicated that almost all SCC mixtures were within the specified range, as stated in EFNARC requirements

Effect of wastewater as sustainable concrete material on concrete performance : A critical review

A massive amount of water has been consumed to produce concrete. The lack of sufficient water for drinking and other essential processes reduces the quantity of water that should be delivered to the people because of the high water consumption by concrete production. All the waste from commercial buildings, households, institutions, and hospitals are known as wastewater. Generally, the water demand is anticipated to increase considerably in the near future. Energy and industry production are expected to witness essential rises in water demand. The enormous quantities of water and generating large quantities of various wastewater from different treatment processes led to exploring different ideas to overcome these issues. One of these ideas is the utilization of wastewater in the construction industry, particularly in concrete mixtures and curing. In the literature, a lack of sufficient studies is obtainable for concrete production from wastewater. This study reviews the chemical composition and physical properties of wastewater and the durability properties of concrete. The treated wastewater from sewage treatment plants (STP) is utilized acceptably for particular utilization. Using treated effluent (TE) in concrete improves cement paste's setting time and compressive strength more than drinking water. The concrete samples containing wastewater recorded 7%–27% lower porosity than control concrete because of the hydration process of cement with time, in addition to the pozzolan reactions. In terms of rapid chloride penetration examination, the authors detected that the samples containing wastewater recorded higher Coulomb charges than that of the control concrete sample without wastewater at 28 curing days because of the high chloride ions in wastewater than that of tap water. The chloride ion penetration increased due to an increase in the domestic wastewater content. Consequently, there is a critical need to improve various processes to adopt and use wastewater in concrete mixtures. This study recommends using a high volume of wastewater to get sustainable concrete with high performance

The durability of concrete produced from pozzolan materials as a partially cement replacement : A comprehensive review

Recently, the construction industry used innovative, cost-ecofriendly, and efficient materials in infrastructure development to mitigate the negative impact on the environment due to manufacturing Ordinary Portland cement (OPC). Many efforts have been conducted to improve sustainable materials to be used as cementitious material in pozzolanic materials such as fly ash (FA), slag, metakaolin (MK), rice husk ash (RHA), palm oil fuel ash (POFA), silica fume (SF), etc. Therefore, this paper introduced to review the results from previous studies that investigated the influence of waste materials with high pozzolanic materials on the numerous durability properties. The results show many advantages due to using those pozzolanic materials as partial cement replacements for the environment, saving energy and cost, and improving durability. Ground quartz and SF have the highest silica oxide (SiO2) content, it was recorded as higher than 90%, producing more pozzolanic activity than other waste materials. The resistance of the concrete containing POFA against acid and sulfate attacks increased when increasing POFA fineness. Besides, sorptivity values were reduced importantly for the blended concrete samples, the addition of 55% FA in binary blended concrete considerably reduced sorptivity of cement concretes. In addition to that, these pozzolanic materials improved other concrete properties. This paper can be a good base for researchers and construction players to adopt waste materials in improving the durability of concrete. Lastly, numerous possible studies were recommended for future studies

Monoclonal antibodies in immunodiagnostic assays: a review of recent applications

Monoclonal antibodies (mAbs) have proven to be effective biological reagents in the immunodiagnostic assays. This is due to their binding accuracy to many pathogens, thus, making them valuable research tools. Since the discovery of hybridoma technology by Kohler and Milstein, the use of monoclonal antibodies produced by the hybrid cells have been employed in diagnosis of several diseases. Monoclonal antibody production has several procedures with considerable variations, but the principles remain the same. Improvements in the field of cell culture technology have led to the production of improved qualities of monoclonal antibodies. In general, these antibodies are important biomedical reagents used in research, especially in the field of laboratory diagnostics for a number of different types of diseases in humans and animals. Some of the areas where application of monoclonal antibodies triumph are herein discussed. This review is aimed to assess various diagnostic assay techniques where monoclonal antibodies are applied in order to provide a first-hand information, especially for beginners in monoclonal antibody production, characterisation, evaluation and /or its applications in research and diagnosis.Keywords: Monoclonal antibodies, immunodiagnostic, assays, recent application

Effect of Recycled Aggregate Concrete and Steel Fibers on the Strength of Self-Compacting Concrete

The accumulation of waste materials in landfills without treatment threatens public health and the environment. The quantity of solid waste continually increases, causing environmental pollution. One of these wastes that should receive scientific treatment is concrete waste. The use of concrete waste as fine or coarse aggregate in self-compacting concrete (SCC) is one of the useful solutions to this problem. This study aims to reuse concrete waste as coarse aggregate in the production of SCC and find out the influence of different steel fiber contents on the strength of SCC. The steel fibers (SF) were used to reinforce SCC in three different volumes (0, 0.5, and 1 % of concrete volume), and the recycled coarse aggregate (RCA) was used to replace natural coarse aggregate (NCA) in five replacement levels of 0, 25, 50, 75, and 100%. The compressive and tensile strengths of the SCC specimens in the hardened state were determined. The results of the experimental study refer to the steel fiber having a positive effect on the enhancement of mechanical properties, particularly the tensile strength of SCC. The addition of 50% recycled aggregates in the concrete mix contributed to increasing the compressive strength by about 20%. Therefore, it can be said that the dual use of recycled aggregates with steel fibers produced concrete with high specifications compared to ordinary concrete. Another positive effect lies in the disposal of concrete waste, which contributes to an economic return in addition to reducing the effect on the environment

Effect of Recycled Aggregate Concrete and Steel Fibers on the Fresh Properties of Self-Compacting Concrete

Globally, the amount of solid waste is constantly increasing, and its disposal is one of the critical issues in recent research studies. Concrete waste includes the rubble of demolished buildings, whether old buildings or those that have been subjected to earthquakes, etc. This research project aims to improve sustainability in the construction industry by recycling and reusing coarse aggregate that was previously used in concrete buildings. The objective is to utilize this recycled material to produce self-compacting concrete (SCC) and assess its performance in its fresh state. By finding new ways to repurpose materials that would otherwise go to waste, this research contributes to developing environmentally friendly practices and reducing the industry's carbon footprint. Furthermore, evaluating the performance of the recycled coarse aggregate in SCC will provide insights into its potential for future use in construction projects, which could ultimately lead to cost savings and improved efficiency in the industry. Recycled coarse aggregate (RCA) was used as a substitute for the natural coarse aggregate (NCA) with volume ratios of 0, 25, 50, 75, and 100%, and steel fibers (SF) were added to the concrete with different volumes ratios (0, 0.5, and 1 %). Workability tests such as slump flow, V-funnel, and L-box tests were carried out for the mixtures in their fresh state. In general, the results of the experimental work showed that the fresh properties indicated that almost all SCC mixtures were within the specified range, as stated in EFNARC requirements

The Spectrum of Glomerulonephritis in Saudi Arabia: The Results of the Saudi Registry

Only few studies regarding glomerulonephritis, with relatively small numbers of patients, have so far been published from different centers in Saudi Arabia, and have reported conflicting results regarding the patterns, even in the same city. The possible reasons for these differences include the small number of patients in the different studies, differences in the indications for renal biopsies, referral bias, geographical differences, and, sometimes, the non-availability of the necessary diagnostic facilities in the reporting centers. In order to overcome these problems, a registry for glomerulonephropathy was attempted in Saudi Arabia. Six large referral hospitals from different regions of Saudi Arabia participated in this registry. Biopsy reports and clinical information of 1294 renal biopsies were obtained. There were 782 renal biopsies due to glomerulonephritis (GN) accounting for 77.2&#x0025; of the total biopsies. Five hundred eighty seven <i> (72.6&#x0025;) </i> were primary glomerulonephritidis. Focal and segmental glomerulosclerosis (FSGS) (21.3&#x0025;) and membrano-proliferative glomerulonephritis (MPGN) (20.7&#x0025;) were the most common types found in the primary glomerulonephritidis. Membranous glomerulonephritis (MGN) was present in only 10.6&#x0025; of the cases. IgA nephropathy was found in <i> 6.5&#x0025; </i> of the cases. Of the secondary glomerulo-nephritides, systemic lupus erythematosus (SLE) was the most common indication for biopsy <i> (57.0&#x0025;) </i> and amyloidosis was found in only <i> 3.2&#x0025; </i> of the biopsies. In conclusion, FSGS and MPGN were the most common forms of primary glomerulonephritis in adult patients in Saudi Arabia. MGN was not as common as in the western world. SLE was the commonest cause of secondary GN. Amyloidosis was not as common as in other Arab countries. There is a need for more centers from Saudi Arabia to join this national GN registry. Similar registries can be established in different Arab countries, which all would, hopefully, lead to a Pan-Arab GN registry

Prognostic Mutational Signatures of NSCLC Patients treated with chemotherapy, immunotherapy and chemoimmunotherapy

Abstract Different types of therapy are currently being used to treat non-small cell lung cancer (NSCLC) depending on the stage of tumor and the presence of potentially druggable mutations. However, few biomarkers are available to guide clinicians in selecting the most effective therapy for all patients with various genetic backgrounds. To examine whether patients’ mutation profiles are associated with the response to a specific treatment, we collected comprehensive clinical characteristics and sequencing data from 524 patients with stage III and IV NSCLC treated at Atrium Health Wake Forest Baptist. Overall survival based Cox-proportional hazard regression models were applied to identify mutations that were “beneficial” (HR  1) for patients treated with chemotherapy (chemo), immune checkpoint inhibitor (ICI) and chemo+ICI combination therapy (Chemo+ICI) followed by the generation of mutation composite scores (MCS) for each treatment. We also found that MCS is highly treatment specific that MCS derived from one treatment group failed to predict the response in others. Receiver operating characteristics (ROC) analyses showed a superior predictive power of MCS compared to TMB and PD-L1 status for immune therapy-treated patients. Mutation interaction analysis also identified novel co-occurring and mutually exclusive mutations in each treatment group. Our work highlights how patients’ sequencing data facilitates the clinical selection of optimized treatment strategies