Characteristics Of Self Research Articles

Strength and durability characteristics of self compacting recycled aggregate concrete incorporating crumb rubber, fly ash and silica fume

Strength and durability characteristics of self compacting recycled aggregate concrete incorporating crumb rubber, fly ash and silica fume

Experimental Investigation on Self Curing High Performance Concrete

Proper curing of concrete structures is important to ensure that they meet their intended performance and ductility requirements. Therefore an effective in situ curing is necessary to maximize the degree of hydration and to minimize cracking problems due to drying shrinkage. Traditional external curing could not achieve a desired effect due to very low permeability and high chemical reaction in high-performance concrete. So some researches shifted their attention to self curing, a new curing method that may greatly enhance the curing effect on high performance concrete. Super Absorbent Polymers (SAP) are used as self curing agent. SAPs are a group of polymeric materials that have the ability to absorb and retain a significant amount of liquid from their surroundings and to retain the liquid within their structure without dissolving. In this study investigate experimentally and analytically the behavior of exterior beam-column joint and strength characteristics of Self Curing high performance Concrete (SCC) containing Super Absorbent Polymers (SAP) and Silica Fume. In this investigation SCHPC was made by replacement of cement by 10% of Silica fume and Super Absorbent Polymer (SAP) added at a various range of 0%, 0.2%, 0.3%, and 0.4% of cement. The experimental results were then compared with analytical results obtained from the FEM Analysis using ANSYS 14.0. Load Deflection characteristics, Stiffness, Ductility were studied and it is found that the SCHPC has shown good improvement in load caring capacity. Mechanical characteristics like Compressive strength, Split-tensile strength, Flexural strength and Modulus of Elasticity examined. A mathematical model was conducted using SPSS software for the mechanical characteristics of SCHPC.A comparative study between the results obtained from the laboratory and SPSS has been made. The predicted mathematical model for mechanical characteristics produced accurate results for the respective ages when compared with the experimental results. Also, the durability study for Self cuing concrete after 28 and 56 days curing was done by conducting the tests such as saturated water absorption, porosity, Acid resistance, Sea water resistance, Accelerated electrolytic corrosion and Modified sorptivity.

Pineapple fibre as an additive to self-compacting concrete

As concrete being widely used in the field of construction, the demand for the materials used is increased ­rapidly. To meet the growing demand it is necessary to use alternative materials to meet the requirements. The Pineapple leaf fibre (PALF) is a highly available material in larger quantity with lesser water content and higher fiber content which makes it as a desirable material as natural fibre. The workability characteristics of Self ­compaction Concrete (SCC) like flowability, filling ability, passing ability, resistance to segregation and bleeding of concrete were out by using slump cone, U-box, L-box, V- Funnel and J-ring test. The test result shows satisfactory results on the workability of SCC. The fresh and hardened properties of concrete were found at the ages 7 days, 14 days and 28 days for various addition of PALF and various replacements of granite powder with the fine aggregate. The addition of PALF has achieved maximum compressive strength and split tensile strength in all ages of concrete at PALF0.2. The replacement of granite powder with fine aggregate seems to be promising in achieving the maximum compressive strength and split tensile strength at the 10% of replacement.

Investigation on Strength Characteristics of Self Compacting Concrete incorporated with AR Glass Fibers

This project presents the experimental study on self-compacting concrete (SCC) with replacement of cement by various percentage of Silica Fume and Fly Ash. The main objective is to determine the Flexural strength, Compressive strength and Split tensile strength of Self compacting concrete by partial replacement of cement by Silica Fume and Fly Ash. The use of fly ash in concrete today is an important subject and is of growing importance day by day. Using fly ash in concrete many provide both economic advantages and enhanced properties in the production of concrete. The addition of super plasticizer increases the workability of concrete. The work involves making seven types of SCCs mixes. For each mix preparation, twenty-one cube specimens, twenty-one-cylinder specimens and twenty-one beam specimens are cast and cured. The specimens are cured in water for 7 days, 14 days and 21 days. The results show that SCC with 5% SF and 10% gives higher values of Compressive strength, Split Tensile strength and Flexural Strength compared to other percentages of Silica Fume and Fly Ash. According to the SCC result, various percentages of AR Glass Fiber (0.1% to 0.4%) added with the optimum SCC (5% of SF+ 10% of FA) and super plasticizer is mixed with optimum SCC. After each mix proportion, specimens are cast and cured for 28 days in water and hardened properties are determined. The results show that the higher the percentage of glass fiber, the higher the values of concrete Compressive strength, Split Tensile Strength and Flexural Strength.

A Study on the Characteristics of Self and Other Awareness in the Figure Diagnostic Evaluation for Novice Counselors Who have Experienced Burnout

A Study on the Characteristics of Self and Other Awareness in the Figure Diagnostic Evaluation for Novice Counselors Who have Experienced Burnout

Comparison of Antenatal Maternal Mental Representations Between Depressed and Non-depressed Pregnant Mothers

Background: Depression is the most prevalent mental health problem in the pregnant women with significant implications for mother and infant’s health. The content of maternal antenatal representations may be related to their depressive symptoms during the perinatal period. Objectives: This study aimed to compare maternal mental representations between depressed and non-depressed groups of pregnant women. Methods: In a causal-comparative study, participants were selected using an inverse stratified sampling method among pregnant women in the last trimester of pregnancy (depressed mothers = 93, and non-depressed mothers = 97). All participants completed Edinburgh Postnatal Depression Scale (EPDS), Dépistage Anténatal de la Dépression Postnatale (DADP), and semi-structure Interview-R after the consent form. Independent- samples t-test, Two-way ANOVA, and Pearson correlation coefficient were applied to compare maternal mental representations subscales between groups, using SPSS-26. Results: The results showed significantly fewer positive ratings for all subscales of Interview-R, including child, partner, self as mother, and mother as own mother in the depressed group (P < 0.05). In the group of depressed mothers, 57% and 32% of the correlations among the representations of child/self as mother and child/partner were significant, while in the non-depressed group, 28% and 48% of the correlations between child/self as mother and child/partner were significant (P < 0.05), respectively. The characteristics of self as mother and own mother showed significant differences in the depressed group compared to the non-depressed group (P < 0.05). Conclusions: Depressed pregnant mothers are less likely to differentiate themselves from their children compared to non-depressed pregnant mothers. Besids, depressed pregnant mothers perceive themselves as mothers more positively than their own mothers, while the opposite is true for non-depressed pregnant mothers.

The effect of the use of recycled coarse aggregate on the performance of self-compacting concrete (SCC) and its application

The demand for self-compacting concrete is very high because this concrete has high flowability and has resistance to segregation. Natural aggregates are of high value, while concrete demolition materials are abundant and of low value. So that the recycled coarse aggregate can be used as concrete material, this study analyzes the characteristics of Self Compacting Concrete (SCC) using recycled coarse aggregate from construction waste. Tests for aggregate wear, aggregate hardness, compressive strength of concrete and tensile strength of concrete were carried out. The wear test refers to the standard AASHTO T-96-74, ASTM C-131-55 and SNI 2417-2008. This test uses recycled coarse aggregate that has been washed so that the sludge content is clean; after that, it was baked with the used aggregate, the aggregate that passed the 12.5 mm sieve and was retained in the 9.5 mm sieve. The test object is pressurized 40 tons at a speed of 4 tons/minute. Concrete Compressive Strength Test refers to SNI 03-1974-2011, using a scale with an accuracy of 0.3 % of the weight of the concrete, a concrete press machine and a capping machine. While the split tensile strength test of concrete refers to SNI 03-2491-2014, carried out on days 7, 21 and 28 with a cylindrical test object. Variations of recycled aggregates start from 0 %, 25 %, 50 %, 75 %, and 100 %. The design's compressive strength is 25 MPa. The results showed that the recycled aggregates had good gradation, high absorption and low specific gravity compared to natural aggregates. The recycled coarse aggregate reduces the compressive strength of the concrete and causes a decrease in a slump, thereby reducing the split tensile strength of the concrete

Strength and durability characteristics of self compacting concrete (SCC) with recycled aggregate and manufactured sand

The investigations on self compacting concrete (SCC) with recycled coarse aggregate and Manufactured sand (M-Sand) were performed in this current study. The SCC mixtures were produced with the recycled coarse aggregate of proportions of 0 to 100% with step increment of 25% with a ratio of water binder at 0.36. In addition, the mixtures were also prepared by mixing it with M-Sand. The feasibility of utilizing the recycled coarse aggregate in SCC was evaluated through strength an durability studies. The obtained results demonstrated that the SCC produced from these materials can be effectively recommended for their usages in concrete industries.

Characteristics of Self Compacting Concrete (SCC) by the Silica Fume as Portland Cement Substitute

Self-compacting concrete (SCC) is a type of concrete that can flow by itself and can self-compact without using a compactor such as a vibrator. This study aims to observe the effect of cement substitution with silica fume on the compressive strength of concrete. The researchers expect a compressive strength of Self Compacting Concrete up to 500 kg/cm2, although silica fume substituted some portland cement. In order to reduce water use while maintaining the slump flow value of 60±2 cm, a superplasticizer was added at the fixed composition of 1.2% (w/w). The experimental design of silica fume as a cement substitute with a variation of 0%, 5%, 10%, and 15% (w/w). The concrete compressive strength test is carried out under the ASTM C234 standard, while the slump flow value refers to the ASTM C494 standard and the British Standard 5075. Although there was no compressive strength of 500 kg/m2 for all types of cement obtained, it shows that the highest compressive strength of SCC concrete was in the type of OPC cement at 28 days of age.

Characteristics of self–ignition and smoldering of coal dust layer under inclination conditions

In many actual industrial scenes, the coal body and coal dust are not always in the tiled state, but in the inclined situation. A two – dimensional transient numerical model of coal oxidation reaction was established to study the self–ignition and smoldering characteristics of coal dust layers in the presence of inclination angle. The effects of gravity and thermal buoyancy were considered to solve the coupling problem of coal oxidation reaction and air flow. The results show that the growth coefficients of minimum ignition temperature of coal dust with thicknesses of 6.4 mm, 12.7 mm, 19.1 mm and 25.4 mm are 0.117 °C/°, 0.0467 °C/°, 0.033 °C/° and 0.033 °C/°, respectively. With the increase of hot plate temperature, the inclination of coal dust can greatly shorten the ignition delay time (IDT). The ΔIDT of coal dust inclination of 60° is 128 s/°C greater than that of 0°. The movement of high temperature point of coal dust in self–heating development stage is from the inside to the outside, and that in decaying stage is from the outside to the inside. In addition, some interesting phenomena in the process of coal self–ignition and smoldering have also been found. The influence of coal dust inclination on its self–heating is mainly reflected in the location of high temperature points and the spread of smoldering. This study is helpful to understand the characteristics of coal dust self–ignition and smoldering spread in inclined situation, and can guide the prevention of coal dust self–ignition.

Understanding the Difference Between Self-Feedback and Peer Feedback: A Comparative Study of Their Effects on Undergraduate Students' Writing Improvement.

Due to the growing popularity of Assessment for Learning in higher education, self- feedback and peer feedback are often highlighted for their role in improving writing performance. In order to provide appropriate support for students' effective implementation of the feedback, teachers must comprehend the differential characteristics of self- and peer feedback. However, empirical research comparing the two remains scarce, particularly when they are used in combination. In this study, 116 Hong Kong undergraduate students participated in an abstract writing task and engaged in self- and peer feedback processes. The amount, types, and implementation of self- and peer feedback and their effects on writing improvement were analyzed and compared. Hierarchical regression analyses indicated that about 25% of the variance in the students' writing improvement was collectively accounted for by the two feedback processes. One form of feedback contributed about 15% of the variance while the other form explained 10%. Feedback types and the amount of implemented feedback were found to be positive predictors of writing improvement, whereas the overall feedback amount negatively affected the improvement. Moreover, the implementation of peer feedback was found to have a greater effect on the improvement than those of self-feedback. Several pedagogical implications of these findings are addressed.

An Experimental Investigation on The Influence of Nano Silica on The Strength and Durability Characteristics of Self Compacting Concrete

Self-compacting concrete (SCC) is also considered as a concrete which can be placed and compacted under its own weight with little or no vibration without segregation or bleeding. The use of SCC with its improving productions techniques is increasing everyday in concrete production. It is used to facilitate and ensure proper filling and good structural performance of heavily reinforced structural members. Recently, nano particles have been gaining increasing attention and have been applied in many fields to fabricate new materials with novel functions due to their unique physical and chemical properties. Degradation of concrete members exposed to aggressive sulphuric acid environments is a key durability issue that affects the life cycle performance and maintenance costs of vital civil infrastructure. Sulphuric acid in groundwater, chemical waste or generated from the oxidation of sulphur bearing compounds in backfill can attack substructure concrete members. Moreover, concrete structures in industrial zones are susceptible to deterioration due to acid rain of which sulphuric acid is a chief component. In this work 40Mpa self-compacting concrete is developed using modified Nan-Su method of mix design. Slump flow, J-Ring, V-funnel tests are conducted to justify the fresh properties of SCC and are checked against EFNARC (2005) specifications. Specimens of dimensions 150x150x150mm were cast without nano silica and with two nano silica are added in different percentages(1%, 1.5% and 2% by weight of cement) to SCC. To justify the compressive strength for 7 and 28days, specimens are tested under axial compression. Durability properties were also studied by immersing the specimensin5% HCl and5% H2SO4. The particle packing in concrete can be improved by using Nano-silica which leads to densifying of the micro and nanostructure resulting in improved mechanical properties. Nano-silica addition to cement based materials can also control the degradation of the fundamental C-S-H (calcium-silicate-hydrate) reaction of concrete caused by calcium leaching in water as well as block water penetration and therefore lead to improvements in durability.

Research on control algorithm of a automatic driving robot based on improved model predictive control

The automatic driving robot can replace the driver in the traditional test and ADAS test; Model Predictive Control (MPC) is used in the horizontal and vertical control process of high-speed driving. According to the uncertainties and complex constraints of automatic driving horizontal and vertical control, the adaptive improvement of MPC is proposed, which can better adapt to the characteristics of self driving vehicles, sensors and tyres. This paper proposes a multi-layer and multi time automatic driving control strategy based on improved MPC. Visual studio is used to write the upper computer software of the automatic driving robot, which realizes good human-computer interaction. The automatic driving robot is verified in real vehicle test. The experimental results show that the transverse and longitudinal control strategy of the improved model predictive control is stable, and the automatic driving robot can realize the high precision and high dynamic control of vehicle steering, pedal and shift.

Effect of Formwork Liner on Durability and Corrosion Characteristics of Self Compacting Concrete

Recent advancements in improving the quality of cover concrete opened a new pathway known as controlled permeable formwork (CPF). In CPF liner, the air and water molecules were trapped in the concrete/formwork interface to spill/drain from concrete surface, at the same time retaining smaller cement and other fine particles. This novel approach, lowers the porosity of concretes surface area thereby mutually tends to improve/enrich the cement content. Another key advantage of this CPF liner system is its tendency to lower the proportion of w/c ratio (water-to-cement). The present experimental research work intends to analysis the impact of CPF liner regarding factors such as durability, corrosive nature along with chloride ingress of self compacting concrete (SCC) (reinforced) sample. For experimentation, initially the castings of concrete samples were done in relation to CPF liner and impermeable formwork (IMF) samples. Followed by various tests at different operating stages to evaluate rapid chloride penetration, chloride regress, chloride migration and accelerated rebar corrosion. On experimentation it can therefore be summed up as, CPF concrete attained phenomenal ability towards Cl ion ingress by 52%–71%. Moreover, the results also indicated that time for concrete cracking in relation to CPF liner was increased to about 1.8 times in comparison with conventional IMF concrete.

The characteristics of self-care in children with spinal muscular atrophy: an integrative review

Spinal muscular atrophy (SMA) is one of the most common genetic causes of death in children. Recently, European Commission (EU) has approved a new gene therapy based on onasemnogene abeparvovec (Zolgensma) for the treatment of patients with SMA. It is essential that children suffering from SMA also apply self-care methods to maintain their health, monitor their weight and food intake, and use appropriate remedies. Indeed, self-care is a crucial element in the health care system because it is able to improve survival and prevent hospitalizations. The purpose of this review is to systematically explore the characteristics of self- care in children with SMA and the relationship with their parents and the collaboration of health- care professionals. An integrative review of the literature has been conducted. The electronic databases CINAHL, Embase, PubMed, and SCOPUS were searched. Thirteen articles met the inclusion criteria and were reviewed using Whittemore and Knalf's integrative review methodology. The analysis of the 13 articles selected for the review show that previous literature has focused on six prevalent themes: problem solving and care behavior, decision making, optimizing living with an illness, high quality, child-focused homecare, healthcare professionals, and monitoring behaviors. This paper highlights how self-management behaviors depend on four basic aspects: the person (individual, cognitive, and social perceptions), the patient's family (level of knowledge of the pathology, involvement in the management and quality of relationship with the patient), the community (relationships with external social contexts, such as school and other organizations), and the healthcare system (availability of resources and the degree of evolution of healthcare).

The characteristics of self-care in children with spinal muscular atrophy: an integrative review

BACKGROUND Spinal muscular atrophy (SMA) is one of the most common genetic causes of death in children. Recently, European Commission (EU) has approved a new gene therapy based on onasemnogene abeparvovec (Zolgensma) for the treatment of patients with SMA. It is essential that children suffering from SMA also apply self-care methods to maintain their health, monitor their weight and food intake, and use appropriate remedies. Indeed, self-care is a crucial element in the health care system because it is able to improve survival and prevent hospitalizations. The purpose of this review is to systematically explore the characteristics of self- care in children with spinal muscular atrophy and the relationship with their parents and the collaboration of healthcare professionals. METHODS An integrative review of the literature has been conducted. The electronic databases CINAHL, Embase, PubMed, and SCOPUS were searched. RESULTS Thirteen articles met the inclusion criteria and were reviewed using Whittemore and Knalf's integrative review methodology. The analysis of the 13 articles selected for the review show that previous literature has focused on six prevalent themes: problem solving and care behavior, decision making, optimizing living with an illness, high quality, childfocused homecare, healthcare professionals, and monitoring behaviors. CONCLUSIONS This paper highlights how self-management behaviors depend on four basic aspects: the person (individual, cognitive, and social perceptions), the patient's family (level of knowledge of the pathology, involvement in the management and quality of relationship with the patient), the community (relationships with external social contexts, such as school and other organizations), and the healthcare system (availability of resources and the degree of evolution of healthcare).

An Experimental Study on The Influence of Nano Silica on the Strength and Durability Characteristics of Self Compacting Concrete

Self-compacting concrete (SCC) is also considered as a concrete which can be placed and compacted under its own weight with little or no vibration without segregation or bleeding. The use of SCC with its improving productions techniques is increasing everyday in concrete production. It is used to facilitate and ensure proper filling and good structural performance of heavily reinforced structural members. Recently, nano particles have been gaining increasing attention and have been applied in many fields to fabricate new materials with novel functions due to their unique physical and chemical properties. Degradation of concrete members exposed to aggressive sulphuric acid environments is a key durability issue that affects the life cycle performance and maintenance costs of vital civil infrastructure. Sulphuric acid in groundwater, chemical waste or generated from the oxidation of sulphur bearing compounds in backfill can attack substructure concrete members. Moreover, concrete structures in industrial zones are susceptible to deterioration due to acid rain of which sulphuric acid is a chief component. In this work 40Mpa self-compacting concrete is developed using modified Nan-Su method of mix design. Slump flow, J-Ring, V-funnel tests are conducted to justify the fresh properties of SCC and are checked against EFNARC (2005) specifications. Specimens of dimensions 150x150x150mm were cast without nano silica and with two nano silica are added in different percentages(1%, 1.5% and 2% by weight of cement) to SCC. To justify the compressive strength for 7 and 28days, specimens are tested under axial compression. Durability properties were also studied by immersing the specimensin5% HCl and5% H2SO4. The particle packing in concrete can be improved by using Nano-silica which leads to densifying of the micro and nanostructure resulting in improved mechanical properties. Nano-silica addition to cement based materials can also control the degradation of the fundamental C-S-H (calcium-silicate-hydrate) reaction of concrete caused by calcium leaching in water as well as block water penetration and therefore lead to improvements in durability.

Effect of Fly Ash and Un-crushed Coarse Aggregates on Characteristics of SCC

This research paper discusses the change in the workability and strength characteristics of Self Compacting Concrete (SCC) due to addition of fly-ash and use of un-crushed Coarse Aggregate (CA). Laboratory based experimental work was carried out by preparing 12 SCC mixtures among which six mixtures contained crushed aggregate and other six mixtures contained un-crushed coarse aggregate. A total of 550 kg/m3 binder content and fixed Water-Binder (W/B) ratio as 0.35 were used. Two mixtures were controlled by using Portland Cement (PC) and other ten mixtures contained PC and Fly Ash (FA). Slump flow time, slump flow diameter and J-ring height tests were conducted to study the fresh properties of SCC. Furthermore, compressive strength was calculated at 7, 14 and 28 days of curing. The outcomes indicated that the slump flow time, slump flow diameter and J-Ring height for all the mixes are within the limits specified by EFNARC guidelines. The compressive strength of SCCs depends upon dosage of fly ash. Compressive strength for SCCs with crushed CA was better than obtained in case of un-crushed CA. The maximum compressive-strengths were observed as 64.58 MPa and 58.05 MPa for SCC with crushed and un-crushed CA respectively.

PENGARUH JENIS AGREGAT KASAR TERHADAP KARAKTERISTIK BETON SELF COMPACTING CONCRETE

Concrete is a construction material that cannot be separated with modern social life. Self Compacting Concrete is concrete that can condense under its own weight. The purpose of this study was to determine the effect of coarse aggregate types on the characteristics of Self Compacting Concrete concrete. To find out the Self Compacting Concrete criteria, workability and flowability testing is performed using the EFNARC method. And compressive strength testing using SNI 1974: 2011. Based on the results of tests conducted in the laboratory of the College of Natural Fence Technology. The optimum compressive strength value obtained at 28 days with the code specimen K1 20.06 MPa and K2 15.42 MPa. The effect of coarse aggregate which has a smooth surface can reduce the compressive strength in concrete Self Compacting Concrete.

Study on effect of strength and durability parameters and performance of Self Compacting Concrete replacement with GGBS at different dosages

To investigate experimentally, the behavior of exterior beam-column joint and strength characteristics of Self Compacting Concrete (SCC) containing Viscosity Modifying Admixture (VMA), and Ground Granulated Blast Furnace Slag (GGBFS). Since there is no standard method of mix design is available for SCC. Hence mix design was arrived as per the rules of European Federation of National Associations Representing for Concrete (EFNARC). Marsh cone test was used to find the saturation of various kind of cements by adding the dosage of super plasticizer accordingly. In this investigation SCC was made by usual ingredients such as cement, fine aggregate, coarse aggregate, water and ground granulated blast furnace slag at various replacement levels (10%, 20%, 30%, 40%, and 50%), with that the Super Plasticizer (Glenium B233) and viscosity modifying agent (Glenium Stream 2) was used in appropriate amount for achieving the better flow in the concrete. The experiments were carried out by maintaining a constant water-powder ratio of 0.45. At various replacement levels the performance of freshly prepared SCC is checked by conducting tests such as slump flow, T50 slump flow, U-tube, L-box and V-funnel tests. Mechanical characteristics like Compressive, Split-tensile and Flexural strength examined. Also, the durability study for SCC after 28, 56 and 90 days curing was done by conducting a number of the tests like saturated water absorption, porosity, carbonation depth and alkalinity measurement