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Since recycled concrete aggregate (RCA) may reduce the demand for natural aggregate (NA), it is beginning to gain popularity in the construction industry as an alternative to natural aggregate. This study examines the mechanical properties of concrete with recycled aggregate in the city of Mosul. Four replacement percentages were studied (25%, 50%, 75% and 100%) with 0% replacement percentage was used as reference mix. The results show that the compressive strength of recycled aggregate concrete (RAC) mixtures decreased as fine and coarse RCA replacement level raised. This reduction in compressive strength was primarily caused by a weaker interfacial transition zone (ITZ) between the RCA and mortar, which is thought to be the strength-limiting phase in concrete. Additionally, all RAC mixtures' flexural strengths decreased as the fine and coarse RCA replacement level increased. This was due to the porosity and weak strength of the old mortar found in the residual mortar on the surface of the RCA. Also, the greater the replacement level of fine and coarse recycled concrete aggregate, the lower the ultrasonic pulse velocity (UPV). Because the porosity of the concrete is a major determinant of UPV values. [ABSTRACT FROM AUTHOR]

This paper analyzes the reaction turbines such as the Kaplan and Francis turbines. The metals present in it are the major elements of stainless steel which make the turbine corrosion resistant and the other elements are bronze alloys and a small amount of titanium. Francis turbines are widely used for hydropower plants, catering to both small and large-scale operations. However, they face erosion issues, especially in sediment-laden water, impacting performance and turbine breakdown. This study utilized the Grant model to predict sediment erosion in Francis turbine runners under various conditions. Erosion near the outlet side increased linearly with the sediment inflow rate, irrespective of operating conditions. An experimental examination was carried out in the recent revival of a Kaplan turbine utilizing structural steel St 3 (GOST standard). Both the base metal and the welded joints were subjected to mechanical property testing and non-destructive techniques (NDT). Ultrasonic testing (UT) identified problems such as lamellar ripping in the base metal and lack of penetration in the weld metal. Tensile tests revealed less base metal contraction, which is consistent with lamellar tearing. For St 3 steel, the fatigue crack threshold was lower than anticipated, and the rate of crack propagation was noticeably higher. Numerical examination of the turbine covers in several operating modes showed that structural integrity is maintained despite these difficulties. In our field investigation, ferritic stainless steels used in marine environments exhibited susceptibility to pitting corrosion. It is well known that alloying, especially with titanium, can improve resistance to pitting corrosion and change the passive film on the surface. There is disagreement though, over how titanium addition affects ferritic stainless steel's passive film and overall resistance to pitting corrosion. This study addressed these uncertainties through microstructure and corrosion properties analyses. The findings indicate a nearly linear increase in pitting potential with titanium addition. Titanium contributes to TiO2 formation in the passive film, reducing defect density. Titanium also causes the leaves phase to precipitate, which promotes micro-galvanic corrosion. The ferrite phase next to the leaves phase is where pitting corrosion in titanium-alloyed ferritic stainless steels mainly happens. The study demonstrates how titanium affects pitting corrosion, with a focus on micro-galvanic corrosion brought on by titanium addition. [ABSTRACT FROM AUTHOR]

The objective of this research is to study the properties of CLSM that serve the same purpose as the soil used in roads besides determining the feasibility of incorporating cement kiln dust (CKD) in different proportions (5%, 10%, and 15%) by weight of cement. The research examines the possibility of using limestone powder (LSP) to produce CLSM mixtures. In this research, the fresh properties of CLSM (flowability, j-ring, v-funnel, density, segregation, and hardening time) were examined, besides determining the hardened properties (compressive strength, splitting tensile strength, flexural strength, density, and ultrasound pulse velocity) at 7 and 28 days ages. The fresh properties results showed that the mixtures containing (LSP), in which cement was replaced with CKD, fulfilled the requirements of CLSM used in roads. However, the hardening time increased with increasing the content of CKD due to the high content of lime and alkali present in CKD. The results of the hardened properties showed that the 28 -day compressive strength increased when replacing 5% of cement with CKD, but the strength decreased at (10% and 15%) CKD replacement compared to the control mixture (0% CKD). The splitting and flexural tensile strength of CLSM decreased at (5% and 10%) CKD replacement, while both strengths increased when 15% of the cement was replaced with CKD. The results of the ultrasound pulse velocity test, revealed that the velocity of wave transmission decreased with increasing the percentage of CKD replacement. [ABSTRACT FROM AUTHOR]

This study deals with the effect of using polyvinyl plastic waste (PVC) as a partial replacement for fine aggregate on the physical and mechanical properties of normal concrete. Natural sand (fine aggregate) is partially substituted by equivalent weight ratios of PVC waste particles, while other proportions of the concrete mixture remain unchanged. The physical tests include density, absorption, and ultrasonic pulse velocity. As well as mechanical tests for compressive, splitting, and flexural strengths are performed in addition to the modulus of elasticity. All specimens are tested after 7, 14, and 28 days. The results of the experiments showed that the incorporation of PVC particles affected the physical and mechanical properties of the concretes produced. Physical properties (density and ultra sound velocity) reduced as PVC ratios increased, whereas absorption rate is increased. Furthermore, when comparing the compressive, tensile, and flexural strengths of partial substitution ratios ranging from 5% to 15%, the results showed that the specimens with partial substitution ratios above had increases of 5.6% –10.19%, 3.125% –15.625%, and 1.61% –6.45%, respectively, when compared to the reference specimens. While the modulus of elasticity decreased as the PVC content increased. In conclusion, the results showed that when the PVC content exceeds 15%, the strength characteristics decline. [ABSTRACT FROM AUTHOR]

The mechanical property of compressive strength in concrete is an essential factor that is indicative of structural stability, which cannot be denied. Recently, the utilization of pozzolanic material, namely fly ash, has attracted considerable attention due to its numerous advantages in tackling environmental and economic phenomena. Consequently, the implementation of this approach has the potential to reduce CO2 emissions and conserve raw materials for sustainable construction. The goal of this study is to find out how adding different amounts of fly ash to cement (0%, 20%, and 30%) affects the compressive strength of concrete when it is heated to high temperatures (from 20 C° to 1200 C°). The present investigation employed non-destructive compressive strength tests using ultrasonic testing based on determining the wave propagation velocity and direct compressive strength. The specimens were designed to detect compressive strength under different levels of temperature with a constant water-bender ratio of W/B = 0.452. The study involved a total of 63 concrete cubes, each with dimensions of 150 * 150* 150 mm, divided into different categories. The average compressive strength of three cubes at each temperature level has been measured after 28 days of concrete casting. The results exhibited a significant increase in compressive strength with the addition of fly ash up to 400 C°, accompanied by cracks. This indicates an increase in the durability of construction exposed to high temperatures. [ABSTRACT FROM AUTHOR]

Advances in nanotechnology today vary widely when viewed from the background of its application, the volume of nanoparticles has become the focus of researchers in the last decade. Hybrid nanoparticles are advances in the world of nanotechnology in which nanoscales of different sizes are added to each other using either the one-step method or the two-step method. This study intends to examine the hybrid titanium oxide-aluminium oxide (TiO2−Al2O3) nanoparticles by looking at the ratio of the volume to mass of different nanoparticles with different proportions of TiO2 (80%) and Al2O3 (20%) nanoparticles added with basic liquid with a fixed volume concentration of 0.1%. Ultrasonic testing and magnetic stirring ensure the stability of nanofluids as well as a way to synthesize nanofluids. Characterization of hybrid nanoparticles using x-ray diffraction (XRD), fourier transform infrared (FTIR) and scanning electron microscopy (SEM) analysis to determine the phase of the crystalline material and see the morphology of the microstructure. The incorporation of TiO2+Al2O3 nanoparticles when viewed from the thermal conductivity and viscosity testing efficiently shows that the thermal conductivity has increased compared to the decreased viscosity, therefore hybrid nanofluids have a potential influence on the heat transfer system for increasing thermal conductivity and low viscosity. [ABSTRACT FROM AUTHOR]

Extensive research has been conducted on the development of Slurry Infiltrated Fiber Concrete SIFCON and its characteristics. Fly ash was used as a binder in this study, and two different kinds of steel fibers—micro and hooked steel fibers—were used in the mortar in variable ratios (0, 6, 12, and 18) to examine the properties of SIFCON geopolymer concrete. The optimization of the geopolymer slurry texture, compression strength, hardness, ultrasonic pulse-velocity, elastic modulus (dynamic) (Ed), shear modulus (dynamic) (Gd), and the logical correlation among non destructive testing (NDT) (RN and UPV) and compression strength were all examined. The test outcomes demonstrated impoved characteristics, such as a 26.1% increase in compressive strength when 12% micro fiber of steel was used. The value of ultrasonic pulse velocity (UPV), which includes shear pulse velocity (Vs) and longitudinal pulse velocity (Vl) showed increases of 33.70% and 27.50% respectively, with the addition of 12% micro fiber of steel. Insertion of 12% hooked-end steel fiber, however, produced ideal rebound number readings. [ABSTRACT FROM AUTHOR]

The article presents the results of experimental studies of the coagulation of fog particles in order to disperse it due to ultrasonic exposure. To determine the effectiveness of ultrasonic coagulation a specialized stand was developed that allows the formation of fog with the required characteristics. The studies made it possible to estimate the meteorological visibility range depending on the exposure time. It has been established that in the presence of air flows and ultrasonic exposure, the maximum efficiency of coagulation is ensured, while the time to reach the meteorological visibility range of 100 meters is reduced by 3 times (110 seconds) compared to the time of natural precipitation. It has been established that in order to increase the range of ultrasonic exposure for the purpose of scoring open spaces, it is necessary to provide a coherent addition of acoustic waves emitting from different areas of the emitter. Therefore, the use of focusing emitters that provide a high intensity of ultrasonic exposure (more than 170 dB in focus) is an effective way to destroy fogs in open areas. [ABSTRACT FROM AUTHOR]

Bricks are the extensively used construction material in building Walls, Pavement, & Other Elements in Masonry Construction. Clay Bricks Are a substantially used material for construction but ongoing days the huge production of brick consumes the quantity of clay which results in topsoil removal and land degradation. Currently, there are several waste materials utilized in construction like Fly Ash, Slag, Silica fume, tire rubber, cement kiln dust, coconut coir, etc. With the rapid climb in urbanization at a mean of 6 % per Annum, brick production has increased. This paper presents the on Fly ash brick with the addition of coconut coir and admixture (BRICK PLUS ULTRA). Fly ash, Cement, Quarry Dust, Sand, Coconut Coir, and Brick Plus Ultra Admixture are being used in this Research paper. Coconut coirhas increased in usage at an interval of 5%, 10 %, and 15 %. Admixture is mixed as rather than the weight of Fly ash 0.1 %, 0.2 %, and 0.3 % is used. The specimen was cast with different combinations like Fly Ash Brick with coconut coir, Fly Ash brick with admixture, Fly Ash with coconut coir and admixture. The specimens were cast and therefore the Compressive Strength Test was done for standard days (7 days, 14 Days, and 28 days). The most important objective of this paper is to understand the physical Properties, Ultrasonic Pulse Velocity Test and behavior of Bricks with the Addition of Coconut Coir and Admixtures in different proportions. [ABSTRACT FROM AUTHOR]

This research was carried out to evaluate the effect of incorporating recycled waste plastic fiber in the rubberized concrete mixture. The waste plastic used in this study is Polyethylene terephthalate (PET) fibers. crumb rubber aggregate recycled from waste tires was used in the production of rubberized concrete, as well. The rubber aggregate was used as a partial replacement by volume of fine aggregate with two percent 10% and 20% in combination with 1% PET fiber by volume of concrete. The experimental work consists of the determination of compressive and tensile behavior for PET rubberized concrete. Moreover, non-destructive tests including hardened density and ultrasonic pulse velocity (UPV) were also conducted. The results showed that the addition of crumb rubber reduced the mechanical strengths, and the addition of PET fiber can balance this reduction. The rubberized PET fiber concrete is a promising material for some structural applications with low to moderate strengths. [ABSTRACT FROM AUTHOR]

Sifcon is manufactured using steel fibers. in this research, plastic fibers (wpfs) produced by cutting soft drink bottles and slurry were used for the purpose of producing sifcon. the fibers were added in different volumetric ratios, as three volume percentages (3%, 6%and 10%) of the total volume of the concrete mixture and the reference concrete mixture was produced for the purpose of comparison. several tests were carried out on the models that were produced such as compression strength tests, flexural strength tests, and other tests. the analysis of the results showed that the use of plastic waste fibers improved the properties of flexural strength compared to the reference concrete. and variation with compression strength. also showed that by increasing the percentage of fibers there was a decrease in density and decrease ultrasonic pulse velocity recorded in this study when increase in fiber plastic ratio. [ABSTRACT FROM AUTHOR]

This study aims to reuse plastic waste from the gas bottle valve manufacturing process in concrete. This type of waste plastic was used as a partial substitute for natural fine aggregate (sand) by volume with different proportions (10%, 20%, and 30%). The influence of these ratios on the characteristics of fresh concrete (slump and compaction factor) and hardened concrete (density, compressive strength, absorption, and the velocity of ultrasonic pulse) have been examined and compared with the reference mixture (without waste plastic). It was noticed from the results that 10% had less effect on the characteristics of concrete, i.e., the properties of 10% waste plastic samples were the same or a little better than reference one. At the same time, the percentage of 30% waste plastic had significantly affected the properties of concrete compared with the reference by decreasing the previous properties sharply. [ABSTRACT FROM AUTHOR]

This research presents an experimental investigation of enhancement of the mechanical properties of ferrocement mortar by adding waste plastics to ferrocement mortar that result from cutting polyethylene terephthalate (PET) bottles as fibers. One reference mix and three other mixes contained Polyethylene Terephthalate (PET) fiber by a volumetric ratio of plastic fibers (0.5, 0.75, and 1 %) were prepared. For each mix, three cube samples were made to test the compressive strength, and three prisms were made to test the flexural strength (modules of rupture). Experiments indicate that the addition of plastic fibers to ferrocement mortar increases the compressive strength and modulus of rupture at 28 days by 17.63 per cent and 5.45 per cent, respectively, for a volumetric ratio of 0.75%, which represents the optimal ratio of fibers as compared to the reference mix. Adding waste plastic fibers to ferrocement mortar leads to reduction in the ultrasonic pulse velocity and the density, and increase water absorption of ferrocement mortar containing this kind of fibers compared with the reference mixture. [ABSTRACT FROM AUTHOR]

Concrete is a vital component of construction and development industry which mainly consist of coarse aggregates. Coarse aggregates as a significant constituent of concrete contributed substantially to its strength concerning the aggregate's characteristic. The verdict discloses that granite and recycled concrete have a good size gradation. The highest value for bulk density was manifested by the river gravel (1.69 kg/l). Granite exhibits the highest value for specific gravity (2.762). Highest percentage of water absorption was demonstrated by recycled tiles (6.09 %). River gravel appears to be the most workable based on its highest slump value (73 mm). Concrete with recycled concrete as coarse aggregates manifested the highest strength (35.015 MPa) followed by concrete with granite (34.810 MPa), recycled tiles (30.793 MPa) and river gravel (30.759 MPa). Rebound hammer test disclosed that recycled concrete and granite manifested the highest rebound number (11). Granite manifested the highest value of 5.282 km/s for ultrasonic pulse velocity test. Based on the tests conducted, each concrete samples exhibit different properties and the recycled concrete manifested potential in high strength concrete production. [ABSTRACT FROM AUTHOR]

API 5L Gr. X65 PSL2 or DNV L450 with NACE compliance line pipes are successfully being used for sour pipeline application over a long period. Subsea pipelines are mostly designed, using strain-based approaches, to operate under thermal longitudinal tensile stress levels approaching and exceeding the pipe material yield strength. From an economic pipelay perspective from offshore barges, mechanized GMAW has now been successfully used for pipeline applications for over thirty years and has achieved an impressive record in improving productivity over that time. The GMAW process, therefore, represents the current state-of-the-art and represents the benchmark against which other welding processes have been used in offshore pipeline applications. To maintain the productivity benefits of the mechanized GMAW process, especially in the sour service application, the main concern is the integrity of the butt welds made using the mechanized GMAW process. Common weld flaws found in this welding process such as lack of fusion or penetration are unavoidable which presents a concern that they may propagate by fatigue and fracture, under operational stresses, to cause hydrocarbon release. It has also been found that automatic ultrasonic testing (AUT) is the suitable Non-Destructive Testing method to detect weld defects such as lack of fusion or penetration in narrow grove bevels used in pipeline girth welding using mechanized GMAW process. Nowadays, weld integrity is confirmed by fracture mechanics analysis, called engineering critical assessment (ECA), which predicts a maximum allowable flaw size for the automated ultrasonic testing (AUT) conducted on the pipe lay vessel (barge). In order to achieve constructible ECA-based alternative flaw acceptance criteria for pipeline girth weld of the sour pipeline, it has been found that an innovative method of developing welding procedure using mechanized GMAW process for API 5L Gr. X65 or equivalent pipeline installation is a suitable constructive approach based on offshore industrial experience. In this study, the effect of several input parameters related to design, line pipe manufacturing, welding consumables, and process on welding procedure development are described and principles behind the need are covered provided based on welding procedure qualification performed. [ABSTRACT FROM AUTHOR]

In this study, lightweight geopolymer concrete was produced based on slag as a binder and using two types of lightweight aggregates (the first type is pumice aggregate resulting from pumice stone crushing, and the second type is bentonite aggregate resulting from converting bentonite clay into aggregate through several stages). This concrete can be considered more environmentally friendly because of its use of slag as a binder and slag as it is known to all that slag is an industrial waste. After pouring the samples and completing the curing period, the compressive strength test was performed and two non-destructive tests (the ultrasonic pulse velocity test and the rebound number test), and then a relationship was found between the compressive strength on the one hand and the non-destructive tests on the other hand, and this relationship is considered very important to estimate the compressive strength of a structure or wall forming of the same type of concrete that has been subjected to certain conditions or dilapidated building through non-destructive tests. As for the best lightweight concrete mix, it is LBB, which contains fine aggregates of bentonite and coarse aggregates of bentonite with a grade (5-25), as it gave a compressive strength of 26.4 MPa. [ABSTRACT FROM AUTHOR]

Ultrasonic testing is used in industry to provide information, bond testing, thick profiling and in service crack detection. In this research, there are three types of ultrasonic testing that are used to detect the discontinuity on the welded joint which is Phased Array UT, Time of Flight Diffraction (TOFD) and Full Matric Capture/Total Focusing Method (FMC/TFM). The objectives of this research are to analyze the discontinuity on the welded joint of carbon still pipe, to identify the difference between all the advanced ultrasonic testing and lastly to determine which techniques is the best to detect the discontinuity on the welded joint. Before beginning inspection on any material, certain calibration needs to be executed so that the data taken is more accurate and trustable. This data can be used to determine the cause of the discontinuity and the appropriate corrective measures. All data that was taken is put into statistical manner by using Excel. The data was analyzed by finding the mean and standard deviation. Determination of the most accurate techniques was based on the closes value of standard deviation to the standard deviation of the reference. Standard deviation measures the dispersion of the data in relation with the mean. To put it in a simpler way, the closest to zero the standard deviation is, the closer to the mean the values in the studied dataset are. [ABSTRACT FROM AUTHOR]

The main aim of this study is to develop a sustainable self-compacting-equivalent mortar by partial replacement of cement with supplementary cementitious materials (SCMs) such as ceramic waste powder (CWP) and glass waste powder (GWP). The replacement levels of SCMs are 5%, 10% and 15% (by weight). A total of sixteen mixes were cast, including a control mix, three mixes each for GWP and CWP, and nine mixes for a combination of GWP and CWP. Two tests were done in the fresh state: slump flow and flow time. The compressive strength, flexural strength, and ultrasonic pulse velocity (UPV) of equivalent mortar mixes were tested to investigate their hardened properties. The beneficial influence on fresh characteristics was measured using GWP and CWP, and the majority of the values were observed to be within an acceptable range according to the EFNARC standard. The equivalent mortar mix prepared with a combined usage of 5% GWP and 5% CWP (i.e., 5-5-2 mix) demonstrated the greatest strength, which increased to 20% more than the reference strength. The increased SCC performance was mostly due to SCMs pozzolanic behavior and finer particle size, as well as better filling property. The study indicated that CWP could be used up to 5% and GWP could be used up to 10% as a partial replacement of cement in SCC, respectively. which not only reduces costs but also provides sustainability. [ABSTRACT FROM AUTHOR]

Ordinary Portland Cement is among the most widely used building materials in recent years. Cement manufacturing emits one ton of CO2 per ton of Portland cement. Therefore, this led to concern about the environment's degradation. This research investigated the effect of a binary mixture that contains limestone powder (up to 15%) and slag (up to 30%) with ordinary Portland cement, using different proportions of 20%, 25%, 30%, 35%, 40%, and 40% by replacement of cement to produce green mortar and select the best proportion. Several tests were performed, and the properties of the mortar curing at 7 and 28 days were studied for eight mixes. Tests have been conducted on flowability, flexural strength, compressive strength, dry density, ultrasonic pulse velocity, and water absorption. The test results indicate that using the binary mixture to produce green mortar when SCMs that contained limestone powder and slag were increased led to reduced flowability. Therefore, increased dosages of superplasticizers have been added to reduce water demand. The results showed that replacing (30%) of OPC with (10% limestone and 20% slag) in the presence certain dosage of superplasticizer, gave the higher compressive strength and flexural strength among other mixes. [ABSTRACT FROM AUTHOR]

This study investigates the use of industrial wastes like Ground Granulated Blast-furnace Slag (GGBS) and Fly ash to make lightweight aerated Geopolymer concrete blocks. The concrete mix proportion of one-fourth of GGBS is used as binding material, and three-fourths of Fly ash is used as a Fine aggregate with suitable Alkaline Activator Solution (AAS). The GGBS and Fly ash are preliminarily tested for specific gravity before the trial mixes. To make the Geopolymer concrete blocks light-in-weight, the aluminium powder is added as an aerating agent, and it varies from 0.06%, 0.045%, and 0.03% to the weight of the binder, and 10M of NaOH solution is added with the Na2SiO3 solution as Alkaline Activator Solution. The fresh concrete in the cubes are cast and placed in oven at 60°C for 24 hours. The changes in the characteristic strength and density of the blocks are observed. The characteristic compressions strength, Water absorption, Density, and Ultrasonic pulse velocity tests are conducted as per IS 6441 & 13311 standards for Aerated concrete. For 0.06%, 0.045%, 0.03% of aluminium powder the observed characteristic compressive strength & density were 4.47 MPa & 1000 kg/m3, 6.05 MPa & 1160 kg/m3, 12.66 MPa & 1270 kg/m3 respectively. Also, the casted cubes are placed in ambient temperature, and the characteristic compressive strength of the ambient cured blocks is 3.77 MPa, 5.11 MPa, and 10.95 MPa for the same percentages of aluminium powder used in the concrete mix. [ABSTRACT FROM AUTHOR]

In the present research work, the slump, compressive strength, flexural strength, split tensile strength, modulus of elasticity, ultrasonic pulse velocity, density and water absorption of Ultra High Performance Concrete (UHPC) with different percentage of nano ZrO2 particles has been investigated. The cement was replaced by nano ZrO2 particles at 1 %, 2 %, 3 %, 4 % and 5 % by weight. Results of this research work clearly show that 3% nano ZrO2 was optimum. It reduces the workability and the mechanical performance of UHPC due to its smaller size, higher Specific surface area and high pozzolanic reactivity of nanoZrO2 particles. [ABSTRACT FROM AUTHOR]

The paper discusses the main techniques of masonry quality control and those to estimate the condition of existing stone structures. The study is aimed at analyzing the existing control techniques, reviewing a practical example of applying them when inspecting a typical brick building, and identifying the essential aspects of arranging masonry quality control to be considered when developing material and engineering documents. Materials and methods: the practical application of visual, destructive, and non-destructive techniques of masonry quality control have been considered. Results: the outcome of a comprehensive inspection of stone structures by visual, destructive, and ultrasonic surface-sounding techniques is provided; the test conditions and the basic requirements for the correct data processing, performing the necessary calculations, and building dependencies have been determined. Recommendations are given for planning the quality control of stone structures at the stage of material and engineering preparation of construction in present-day conditions. Conclusions: quality control of stone structures is used in both the construction of new facilities and inspection of existing buildings. Control or inspection techniques are chosen at the method statement development stage while considering the specifics of applying a particular technique and the permissible measurement error; in practice, a combination of several control techniques is often used to obtain more reliable results. [ABSTRACT FROM AUTHOR]

The present work is an attempt to partially replace the coarse aggregates in concrete by the rubber aggregates and to study their impact on mechanical properties of the obtained lightweight concretes. In fact, the rubber aggregates have less specific gravity and are available in huge amounts worldwide. To produce our lightweight concrete, we replaced coarse aggregates with rubber aggregates by varying the replacement proportion from 0% to 30% with increment of 10%. The obtained samples were subject to several heating / cooling cycles from 25 ° C up to 600 ° C. Then, the sonic auscultation, tensile and compressive tests were carried out to assess the effect of temperature variation on the mechanical properties. [ABSTRACT FROM AUTHOR]

Concrete is a material made of coarse aggregate, fine aggregate, cement, and water. However, the use of cement is not environmentally friendly because it produces CO2 due to the cement clinker combustion process at a temperature of 1450°C. Therefore, another alternative is needed to replace cement as the basic material for making concrete. Fly ash is an alternative material to replace cement which, when it is activated with an alkaline solution, can harden. The scientific term for the manufacture of cement-free concrete using fly ash and an alkaline solution is geopolymer concrete. The strength of geopolymer concrete is expected to have the same resistance or compressive strength value as cement concrete. Testing the compressive strength can be used to find out the value of the compressive strength of the concrete that has been made. There were two types of test properties used in this study: destructive tests and nondestructive tests. In this study, 51 pieces of cylindrical specimens measuring 15 cm x 30 cm were used and 34 specimens were beamed with dimensions of 15 cm x 15 cm x 53 cm. The molarity used was 8M, 12M, 14M and 16M with steam curing at a temperature of 80°C - 90°C for 4 hours as the test object treatment method. The result obtained in this study is the magnitude of the correlation coefficient which is used as a quantity to obtain the test value to represent the destructive test in the form of cylinder compressive strength in geopolymer concrete. The correlation coefficient value obtained in the compressive testing of the core drill is y = 19.497e0.0214x with the coefficient determination of the exponential regression is 0,6552. The correlation coefficient value obtained in ultrasonic pulse velocity is y = 11.415e0.3441x with the coefficient determination of the exponential regression is 0,5306. [ABSTRACT FROM AUTHOR]

An investigation has been made to perceive the correlation of normal concrete compressive strength between the destructive and non-destructive test method. The non-destructive method used Ultrasonic Pulse Velocity Test. Meanwhile, destructive method used a concrete compressive test. Testing the compressive strength of concrete using cylinder concrete samples. The cylinder concrete samples used in this study had a concrete mix design of 25 MPa and 30 MPa. Each sample was tested destructive and non-destructive to get the compressive strength value relationship. Based on the result, the regression model proposed to estimate the compressive strength of concrete is the first regression model which is f'ce=0,0037v1+12,346. The results are validated using column structure located in K2F Room on BINUS Syahdan campus. The validation result shows the estimated compressive strength from the linear regression model is higher than the projected compressive strength of the concrete column. [ABSTRACT FROM AUTHOR]

The global production of paper is on the rise, thus leading to increasing amounts of waste in different stages of paper manufacture. Paper sludge waste is the most abundant and there is a big potential to reuse it after appropriate processing. This research paper analyses paper sludge waste fired at 900°C temperature for 2 h in terms of mineral composition, particle density and water demand in cement-based mixtures, as well as the effect of paper sludge waste on the density, ultrasonic pulse velocity, compressive strength and mineral composition of cement-based specimens. In the cement paste mixtures 0%, 2.5%, 5%, 7.5% and 10% of cement was replaced with paper sludge waste fired at 900°C temperature for 2 h. The ratio between water and solid substances was 0.35. Gehlenite and calcium oxide were found to prevail in the mineral composition of paper sludge waste, whereas water demand of cement-based mixture incorporating paper sludge waste increased 30%. The intensity of XRD curves revealed that a higher content (more than 7.5%) of paper sludge waste fired at 900°C temperature for 2 h in the mix increases the amount of portlandite and reduces the amounts of cement minerals: alite and belite. An empirical equation was drawn on the grounds of statistical analysis to calculate the compressive strength according paper sludge waste content fired at 900°C temperature for 2 h. The correlation and determination factors more than 0.9 demonstrate that the change of compressive strength in relation to paper sludge waste content can be described by the second degree polynomial equation and the optimum content of paper sludge waste fired at 900°C temperature for 2 h in the cement matrix is 5%. The highest density and ultrasonic pulse velocity values of cement stone specimens after 28 days of curing were obtained of specimens containing 5% paper sludge waste. [ABSTRACT FROM AUTHOR]

The aim of this investigation is to study the effect of using scrap tires recycled steel fibers on some hardened properties of sustainable self-compacted concrete (SSCC) containing crushed waste clay brick as a partially volumetric replacement of natural coarse aggregate. The crushed clay brick waste was used with 15%, 25% as partially volumetric replacements of natural coarse aggregate. The volume fractions of scrap tires recycled steel fiber (STRSF) that had been used in SCC were 0, 0.25, 0.5 and 0.75% with 40 as an aspect ratio in combination with 15% volumetric replacements of crushed clay bricks waste. Six concrete mixes had been prepared to accomplish the purpose of this investigation. The studied properties including, dry density, water absorption, compressive strength, flexural strength, Ultrasonic Pulse Velocity (UPV) and splitting tensile strength. The results illustrate that the increase in recycled steel fibers quantity in self-compacted concrete causes enhancement in hardened properties of GSCC (density, compressive strength, flexural strength, UPV and splitting tensile strength). The water absorption had been decreased with the increase of recycled steel fibers content. [ABSTRACT FROM AUTHOR]

In this article are presented the author's experimental research to determine the in-situ compressive strength of concrete. The probabilistic concrete compressive strength was determined by method of elastic rebound (Schmidt hammer) and ultrasonic pulse velocity method. In-situ concrete compressive strength was determined by destructive testing of cores, taken from reinforced concrete elements. Characteristic in-situ compressive strength was assessed by indirect methods with a relationship determined from a limited number of cores and a basic curve, given in BDS EN 13791:2007/NA:2011. [ABSTRACT FROM AUTHOR]

This paper deals with a determination of freeze-thaw resistance of concrete and the evaluation is based on monitoring of three properties of concrete. Six concretes produced with identical components were prepared for the experiment. The concretes only differ in the amount of cement and plasticizing and air-entraining admixtures. The concretes were subjected to freezing and thawing cycles and their dynamic moduli of elasticity and flexural strengths were determined after 50 and 100 cycles. The moduli of elasticity were determined using the resonance and ultrasonic pulse velocity methods. The output of the paper is an evaluation of how the individual properties react to the damage to the internal structure of the concrete. It was found that the highest decrease occurred in flexural strength whereas the lowest decrease was observed in the case of the relative dynamic modulus of elasticity determined by the ultrasonic pulse velocity method. [ABSTRACT FROM AUTHOR]

The paper describes an experiment aimed at verifying the influence of the size of large-format tile segments and, primarily, the influence of various adhesives on the quality and behaviour of the tiles. Large-format tiles were attached in various ways to pre-prepared concrete panels with a thickness of 150 mm and surface dimensions of 2 m x 3 m. The adhesives used were varied as well as the size to which the large-format elements were cut. The quality of the tiling material was monitored non-destructively by running an ultrasonic pulse velocity test. It was found that while the size of the segments cut from the large-format tiles did not affect the ultrasonic pulse velocity, the adhesive used did. [ABSTRACT FROM AUTHOR]

The article considers the author's experience in examining the technical condition of structures strengthened with CFRP systems. Destructive and non-destructive methods of quality control of CFRP applications specified in Russian and foreign design standards are analyzed. Nowadays CFRP systems have become a very popular solution for strengthening of concrete structures because of its lightweight and the ease of application. But due to some gaps in standards regarding quality control there is still a problem for technical staff accepting strengthening works. Own author's experience was considered when conducting a survey of the technical condition and designer's supervision of the work on strengthening reinforced concrete structures with CFRP. During the designer's supervision and inspection of structures, the method of infrared thermography was successfully tested, which allows for quality control of the application of the external CFRP system in a non-destructive way, especially in hard-to-reach places and over large areas. It is believed that the use of IR Thermography can result in cost savings of 60 to 75% over ultrasonic testing and radiography, two of the commonly used NDT techniques. It can be concluded from the literature review that the issues of the presence of defects in the CFRP application and their permissible percentage ratio during the acceptance of works and inspection of buildings are poorly regulated. [ABSTRACT FROM AUTHOR]

Geopolymer concrete could be an alternative of the conventional concrete due their quality and performance in different conditions. In this study, to investigate the effect of curing period on the mechanical properties of the geopolymer concrete specimens. The specimens were cured in the oven at 600C for 4hours to 72 hours, and check the effect of various curing period by the density, drying shrinkage, compressive strength, splitting tensile, flexural strength, poison's ratio, elastic modulus, rebound strength and ultrasonic pulse velocity test. After the experimental investigation, it is concluded that the compressive strength, splitting tensile, and flexural strength increases rapidly from 4hours to 24hours of the curing period but after the increment of the curing period shows a little bit increment. The maximum elastic modulus was found at 72hours curing period specimens, whereas the minimum elastic modulus was found at the 4hours curing period specimens. The maximum density was found at the 4hours curing period specimens, whereas the minimum was found at 72hours curing period specimens. The rebound strength and ultrasonic pulse velocity show a similar pattern to the compressive strength of the specimens. [ABSTRACT FROM AUTHOR]

Geopolymer concrete could be an alternative of the conventional concrete due their quality and performance in different conditions. In this study, to investigate the effect of river sand replacement to the stone-dust on the mechanical properties of the geopolymer concrete specimens. Slump, density, compressive strength, splitting tensile, flexural strength, poison's ratio, elastic modulus, rebound strength, and ultrasonic pulse velocity tests were performed on the specimens after they had been cured in the oven for 24 hours at 60°C. After the experimental investigation, it is concluded that the compressive strength, splitting tensile, and flexural strength increases with the replacement of river sand to stone dust in the mix design. The elastic modulus of river sand used specimens and stone-dust used specimens are 23.2GPa and 23.4GPa, respectively, after 28 days test. The rebound strength graph follows the same pattern as the specimens' compressive strength. The UPV of stone-dust specimens is slightly higher than river sand used specimens. The ultrasonic pulse velocity of stone-dust used specimens and river sand used specimens are 4.22km/sec and 4.16km/sec, respectively, after 56 days test. [ABSTRACT FROM AUTHOR]

One of the ways to save raw materials and energy resources is the introduction of non-destructive testing at precast concrete factories as an integral part of comprehensive quality control. This article discusses non-destructive methods for determining the strength of concrete, describes and presents the results and analysis of studies. Two main test methods were identified and compared - drilling and ultrasonic methods. Including used a comprehensive test method. The procedure involved a random selection of cubes for each test series. Each type of test was subjected to 10 cubes. Impact, indentation and ultrasonic tests were carried out in accordance with the existing Code. The drilling method was defined as new. According to the test results, graphs are built. Analysis of the graphs obtained gives a more complete picture of the strength properties of materials and structures. Complex tests allow us to assume the further nature of the behavior of materials and structures under the influence of loads in comparison with the case when only one test method is used. One of the ways to save raw materials and energy resources is the introduction of non-destructive testing at precast concrete factories as an integral part of comprehensive quality control. [ABSTRACT FROM AUTHOR]

Experimental work was carried out in this research to study the feasibility of using crushed clay brick waste as a substitute for natural coarse aggregate in concrete, and investigated the ability to reinforce this concrete with fiber from waste materials as an alternative to the commercial fiber. This alternative fiber was made of cut steel Tie Wire (TW) waste with an aspect ratio of 40, a material chosen for its low cost and ready availability. Three concrete mixes featuring 0, 15 and 25% crushed brick waste as a substitute for coarse aggregate were prepared, along with three further batches of 15% crushed brick as coarse aggregate, which were reinforced with different volume fractions (0.5, 1 and 1.5%) of TW waste fiber to produce high performance concrete. Various properties of these concrete mixes, including the compressive, splitting, tensile, and flexural strengths; dry density; and ultrasonic pulse velocity (UPV) were investigated. The results showed that the addition of crushed clay brick waste aggregate causes some reduction in all the studied properties, but that high strength concrete was nevertheless produced at rates of up to 25% crushed brick aggregate. The inclusion of TW waste fiber significantly enhanced the compressive strength of the concrete with 15% coarse crushed brick aggregate, however, allowing high performance concrete with a compressive strength of up to 83 MPa to be produced. The enhancements in compressive, splitting and flexural strengths were 29%, 42.8%, and 38% respectively for concrete reinforced with 1.5% TW waste fiber. [ABSTRACT FROM AUTHOR]

Study on usage of agriculture and food waste as a replacement of building construction materials has become trend due to its potential in lowering the construction cost and reducing the environmental impact. In Malaysia, the demand of durian has kept increasing each year, and so hence, its production. That translates to the increase of durian shell wastage. The burnt durian shell ash has a physical similarity to cement. Hence, the intention to convert durian shell to durian shell ash (DSA) and mixing it into the concrete mixture as a partial cement replacement could help to minimize the environmental issues related to durian shell, and hence minimizing cement use. This study will determine the DSA role as a partial replacement of cement to improve the performance of concrete. DSA was used to replace the cement contents in concrete by weight of 5%, 10%, and 15%. The properties of the concrete are investigated during fresh and hardened state. Workability, setting time, expansion, and fineness of DSA as cement replacement were determined during trial mixes while the test carried out during the hardened state includes compressive strength test, flexural test, tensile test, and ultrasonic pulse velocity test. Results show that the DSA existence in concrete does affects the properties of the concrete. The workability of the fresh concrete decreases as the cement replacement increases and the strength of the concrete decreases as the percentage of DSA in the concrete mixture increases, making it potentially useful in producing a mass concrete. The optimum percentage of 5% of DSA replacement in concrete is possible to produce concrete mix with strength more than 30 MPa. This proves that durian shell ash is a suitable replacement for cement for producing high compressive strength concrete. [ABSTRACT FROM AUTHOR]

This paper discusses experimentally the effect of adding Styrene-Butadiene Rubber (SBR) Sika-Latex on the fresh and hardened properties of concrete. The behavior of polymer-modified concrete and the development of strength were investigated. To doing so, five concrete mixes were made with a variable content of SBR Sika-Latex (0%, 2%, 4%, 6%, and 8%), and the effect of adding these percentages on compressive strength, tensile strength, and density of concrete at different ages (7, 28, 56 and 90 days) was studied. Non-destructive properties such as ultrasound pulse velocity and dynamic elastic modulus were also calculated. The results showed that adding SBR Sika-Latex had a negative role in the compressive strength and tensile strength, as its addition caused a decrease in both strengths. Where the percentage of decrease in the compressive and tensile strengths at 28 days was (7%, 19%, 27.5% and 36.8%) and (5.3%, 18.4%, 26.3% and 36.8 %) respectively when adding (2, 4, 6 and 8%) of SBR Sika-Latex. The polymer-modified concrete also experienced a decrease in its density. Furthermore, the ultrasonic pulse velocity waves decreased with increasing addition ratios. Moreover, the ultrasonic pulse velocity findings were used to predict compressive strength and dynamic modulus of elasticity, and appropriate relationships were obtained that showed a good correlation between these properties. [ABSTRACT FROM AUTHOR]

Nowadays, the essential targets in concrete production are achieving sustainab ility and durab ility. One of the most attractive options for more sustainab le concrete is using supplementary cementitious materials (SCMs) and waste materials as substitution for main concrete ingredients. This study aims to evaluate durab ility aspect in relation to some trans it properties of different six concrete mixtures incorporating high volume of metakao lin (MK), brick powder (BP) and waste aggregates of clay brick and plastic. For reference mix, 50% of cement weight had been replaced with a blend of 25% BP and 25%MK. Meanwhile, other five mixtures had been produced where the natural coarse aggregate was substituted by 30% of its volume with different content of crushed brick aggregate (CB) and shredded plastic aggregate (PA). Transit properties of all mixes were tested through ultrasonic pulse velocity (UPV), water absorption and water sorptivity. The results showed that the control mixture of high-vo lume blended MK-BP concrete had excellent quality grade based on the high trans it velocity of ultrasonic pulse which exceed ed 5.11 km/sec, low water absorption of 2.43%, and slow capillary suction with sorptivity index of 0.01337 mm/sec0.5. Moreover, substitution of natural aggregate by 30% of single or combined CB and PA had adversely affected the pulse veloc ity and water absorption of concrete The water sorptivity index has increased for the mixtures with high CB content, while the presence of waste p lastic aggregate has slightly reduced the water sorptivity, especially for the 15% PA content. The outcomes of this paper have shown acceptable durability aspects for this green concrete, which can be applicable in aggressive environment. [ABSTRACT FROM AUTHOR]

Waste from industrial always be the main issued nowadays where it will contribute to create much pollution to the earth. Biomass waste also one of the problems encounter these days. Therefore, this study had tried to encounter this problem by using cellulose nanofibres (CNFs), a by-product from industrial waste and a biomass waste will be act as waterproofing or as coating on concrete. Scope of study for this coating focused on the physical and mechanical behavior applied on the concrete cubes. Normal concrete cubes with 30 N/mm² design strength were used in this study. These concrete cubes were tested under visual assessments, ultrasonic pulse velocity, static contact angle, capillary water absorption and compressive strength for coated and uncoated condition. The results discovered that the samples with CNFs coating reach the excellent grade quality of concrete with 4.670 Km/s by using ultrasonic pulse velocity (UPV) equipment. Meanwhile, static contact angle result also supported this condition where the CNFs coating can provide near superhydrophobic layer surface with constant static contact angle of 134.1° by using goniometer equipment. Besides, the water droplet on CNFs coating leaves little stain behind compared to uncoated concrete when the concrete cube being tilted to observe for the water droplet. This can be concluded that CNFs coating can provide near superhydrophobic layer surface with water repellent and self-cleaning property. Properly coated concrete give significant on water ingression on concrete too. From destructive test, which is compressive strength test, the mean strength of concrete is 42.03N/mm2 which over the target strength of concrete. Overall, all testing showed that CNFs coating is have good waterproofing for coating. [ABSTRACT FROM AUTHOR]

The propagation of secondary porosity as the result from weathering process created very complex properties of rock structure, both dynamic and engineering properties. In the tropical climate, which has unique weathering process has produced a complex structure of rock which includes the arrangement of pore structure, mineral compositions, grains size and others. The process of weathering involves the wetting and drying, which take place with the presence of water inside the rock microstructure, then further created the numbers of micro-pore which contributing to weakens the rock structure. This study was focused on to analyze the effect of secondary porosity variation due to the weathering of rock to the tropical weathered sandstone that was collected from Kubang Pasu formation located in northern peninsular Malaysia. The block of the rock sample was cored into cylindrical shape with size of 50 mm diameter and 100 mm length using static coring machine in the laboratory. Total 45 numbers of cylindrical samples were cored, at three different grades of weathering (WG) comprises of WG II, WG III and WG IV. The saturation & caliper method were used to determine the porosity percentage, and P-wave velocity by adopting ultrasonic pulse velocity test (UPV). Further investigation was made to evaluate the deformation characteristics of weathered sandstone under the uniaxial compressive stress as well as the crack pattern depending on its weathering grades. It can be concluded that the porosity is the main controlling factor that effecting the other properties of rock. [ABSTRACT FROM AUTHOR]

The dissertation work is focused on the effect of fly ash and alccofine 1203 to achieve High Strength Concrete. High strength concrete requires high amount of cement than the nominal grade. This work focused on the performance of various mixtures which are partially replacing with cement includes 30% fly ash with 0%, 4%, 8% and 12% alccofine 1203, respectively. Concrete specimens are cast for M60 grade as per mix design and the specimens are tested for its mechanical properties. Ultrasonic pulse velocity test was also performed to assess the quality of concrete. [ABSTRACT FROM AUTHOR]

NON-DESTRUCTIVE TESTING (NDT) utilizes the physical properties of a material for detection, location and evaluation of flaws/defects and judging of the microstructure and mechanical properties without damaging the functionality of component being inspected. Flaws or imperfections that are detected by inspection of the component may be obtained by several reasons. It may be due to originality of the material caused by the process used created by some human error or defects initiated during the operating life of components etc. NDT method ranges from the simple to the tangled. NDT is also used for condition monitoring of various components during operation to forecast and assess the rest of the life of components while retaining its structural integrity. Based on availability, accessibility, suitability, analysis and experience the choice of specific method varies. The end result is the saving of time, money and development in precision and reliability of results obtained. There are a vast number of techniques in NDT. Visual inspection testing, liquid penetrate testing, ultrasonic testing, magnetic particle testing, eddy current testing, thermal infrared testing, acoustic emission, leak testing, thermography, instinct metallographic examination. The industrial applications of NDT are mostly found in railways, nuclear, non – nuclear and chemical industries, aircraft and petroleum projects, coal mining industry. This paper presents the knowledge for selection of specific NDT detecting surface flaws and requisite applications. It presents vital aspects in each method along with their advantages and disadvantages. [ABSTRACT FROM AUTHOR]

Estimating the in-situ strength of the concrete is an important factor in planning the execution of reinforced concrete structures. The evaluation of the concrete characteristics development can be based on different methods-maturity methods, temperature-matched curing, rebound hammer testing, ultrasonic pulse velocity and other. The recent article presents the results of an experimental study to determine the compressive strength of the concrete in test specimens by a maturity method based on ASTM C1074-19e1 and a rebound hammer test according to BDS EN 13791/NA and BDS EN 12504-2. The maturity calculation are based on temperature measurements taken at a depth of 10 mm below the surface of the test specimens. Calculations were also performed to assess the compressive strength according to FIB Model Code 2010. The obtained results are compare with the actual concrete strength established by testing cubic test specimens, cured on site. Furthermore, there was found a very high correlation between the values of the compressive strength, calculated by maturity method based on ASTM C1074-19e1 and the rebound hammer test according to BDS EN 13670/NA and BDS EN 12504-2. [ABSTRACT FROM AUTHOR]

In order to become the scientific conference report this article presents in details the experiment results and numerical values received in it. These results can be useful to engineers in the field of employ fiber-reinforced concrete. The research was devoted to the features of determination the compressive strength of fiber-reinforced concrete in existing structures. The methods described in standards and technical documentation, dedicated to the design, manufacture and application of fiber-reinforced concrete structures, were analyzed in case of regarding to the quality control of erected constructions. The results of fiber-reinforced concrete strength studies, carried out within the inspection work on the ground floor slab belonging to a mall under construction, are presented. The application of destructive testing of concrete cylinder samples and two ways of non-destructive testing (NDT) is considered: the anchor pull-out test and the ultrasonic pulse velocity (UPV) test. There is a comparison and analysis of the results obtained using the destructive and non-destructive methods. [ABSTRACT FROM AUTHOR]

An experimental and theoretical study of fracture mechanisms of the AMg6 alloy at different structural levels was carried out under consecutive shock-wave and fatigue tests associated with conventional catastrophic events of aircraft engine components (fan blades) due to the foreign object damage and the life-time decrease in the presence of a corrosive environment. The test program for shock-wave loading of massive flat targets made of aluminum alloy AlMg6 with profiled impactors (explosive generator method) initiating controlled damage of various levels in the volume of the material was implemented experimentally, followed by the application of an ultra-high cycle load (the number of cycles 107–109) on samples specially prepared from the target material samples. Fatigue tests of preloaded samples were conducted on Shimadzu USF-2000 ultrasonic fatigue testing machine with the cooling by abundant compressed-air and salt fog (3% NaCl). [ABSTRACT FROM AUTHOR]

Vehicles are one of the most vital parts of human life to keep up to the needs and demands in the present fast paced world. But often in this haste, the little aspects of safety get ignored which later leads to major causes for grief such as accidents. This paper focuses on solving those problems by using economical and easily available IoTs. The procedure mainly involves usage of ESP32 embedded systems. It can be used in few applications like alcohol detection, accident detection, gas sensing and ultrasonic sensing. In unprecedented times it is helpful if the driver has consumed alcohol or the owner of the vehicle needs to monitor the condition of the vehicle/driver at any time. By using various sensors such as gas sensors, vibration sensors, GPS etc. a system can be developed to provide assistance for safety and emergencies while driving a vehicle. The many advantages of ESP32 makes it favorable for such applications. The validation of this concept is done by simulation in Proteus 8 Professional and also hardware prototype has been prepared. [ABSTRACT FROM AUTHOR]

Engineered Cementitious Composites (ECC) containing high volumes of fly ash (HVFA) as a partial replacement of Portland cement (PC) at different replacement levels (0.8, 1.2, 1.6 and 2) by weight of cement, incorporated either with silica fume (ECC-SF) or with carbon black (ECC-CB) powders have been studied. Physical properties (bulk density, water absorption and ultrasonic pulse velocity [UPV]), furthermore, mechanical properties (splitting tensile strength and compressive strength), were measured at different curing ages (7, 28 and 90) days. In addition, Scanning Electron Microscopy (SEM) were measured. For comparison, control mixture was produced, which was free from any mineral additives. Results showed when utilizing FA instead of PC in mortars at proportions (0.8 & 1.2) can achieve good sustainability material as well as gain the consistency and mechanical strength of ECC. While, when the replacement ratio was raised to (2.0), the ECC mortar becomes heterogeneous and crumble subsequently that lead to giving poor mechanical and durable properties of mortar. Utilizing of FA as cement replacement in mortars at appropriate level, leading to decrease PC consumption as well as providing an economic and friendly environmentally advantages. [ABSTRACT FROM AUTHOR]

The use of mortar has diverse uses due to the advancement in the use of chemical and mineral admixtures with cement matrix mixes. Different mortar mixes have been prepared using 20, 25, 30, 35 and 40 % for the mixes M1-M5. Then the mixes "M6, M7, M8" have been prepared by the combination of calcined clay (CC) and fly ash (FA) in different amounts, such as 40% CC +10% FA, 35% CC+15% FA and 30% CC+ 20% FA, respectively. So, this paper highlights the use of non-destructive test to evaluate the properties of mortar. Thus, different tests have been implemented on the mortar mixes in fresh and hardened state. So, the tests include flow, absorption, dry density and ultrasonic pulse velocity (UPV). The results showed that the use of 20% of calcined clay increases the dry density, whereas, the dry density decreased by the other percentages of cement replacements. Also, the UPV values showed acceptable ranges that refer to good and economic mortar production from these high percentages of cement replacement. [ABSTRACT FROM AUTHOR]

The High Temperature Gas-Cooled Reactor (HTGR) requires the use of the material as a core structure which is resistant to operating temperature reaching more than 500°C. The fine-grained isotropic graphites of IG-110 is a graphite material that has been applied to existing HTGR. The reactor core structure has a function to ensure reactor coolant flow, control rod movement, and reactor fuel conditions. In the implementation of reactor component inspections, various non- destructive test methods have been developed which aim to find cracks that are the initial failure of components. Besides, a non-destructive test method was also developed to measure the stress acting on the reactor components in order to determine the aging process. Currently, stress measurement is generally done indirectly using strain gage. The purpose of this study is to determine the effect of the load on ultrasonic wave velocity. Ultrasonic testing is carried out by using a portable ultrasonic flaw detector, using two types of waves, longitudinal wave and transverse wave, with a frequency of 5MHz. The stress acting on graphite material is compressive. The load was varied at several levels. The test results show that compressive stress in graphite material reduces ultrasonic wave propagation, for both types of waves used. The higher the compressive stress in the material, the more significant the decrease in ultrasonic wave propagation. The testing system used in this study has a level of measurement accuracy when the load value is higher than 20MPa. [ABSTRACT FROM AUTHOR]

Paper waste production in DKI Jakarta according to data from The Jakarta's Environmental Services reaches an average of 40% of total waste production per month for each municipality (kotamadya). On the other hand, Indonesia's necessity of construction development, notably residential home, is increasing constantly along with the amount of Indonesia's population. This condition stimulates innovation of eco-friendly, inexpensive building material with suitable strength. Since 1990's, papercrete, concrete with waste paper as substitution of fine and/ or coarse aggregate, has been studied. Its use for structural materials has evolved and required supporting research for application on larger structural components. In this research, homogeneity aspect of papercrete from domestic waste (office) is investigated along a certain height of vertical beam. To do so, Ultrasonic Pulse Velocity (UPV) propagation measurement on 5 vertical prismatic beam specimens was conducted. By using direct mode transmission, two transducerswere used through 15 cm of width. Rate of propagation can detect the density of concrete at each level since early age of concrete (2 hour after casting). It describes the distribution of material inside. This homogeneity study is beneficial in evaluating papercrete application in real beam structure in the future. [ABSTRACT FROM AUTHOR]