Test Cubes Research Articles

Influence of changing dentition on food texture preferences and perception of eating difficulty in Australian children.

The transition from primary to permanent dentition is an important phase in children's oral development, yet its impact on texture perception and food acceptance are less explored. This study aimed to investigate how changing dentition and tooth loss influence texture preferences and perception of eating difficulty among children aged 5 to 12 years. Children (n = 475) completed a forced-choice questionnaire featuring drawings of six food pairs, each available in hard or soft texture, and reported whether they had started losing primary teeth and the number of tooth gaps present. They also tasted four samples: chocolate snacks (cake and biscuits) and cheddar cheese (grated and cubes), evaluating their perceived eating difficulty and liking for each sample. Analysis of questionnaire responses showed a general preference for softer food textures among children, with a 36% probability of choosing hard foods. Preferences were not related to child's dental state, including primary teeth loss (p = .13) or number of tooth gaps (p = .45). In the taste test, chocolate biscuits and cheese cubes were perceived as significantly more difficult to eat than chocolate cake and grated cheese, respectively (both p < .0001). Children with more than two tooth gaps reported greater eating difficulty for chocolate biscuits and cheese cubes compared to children with fewer or no tooth gaps. This study demonstrated that children's texture preferences for hardness of foods remained consistent during dentition change, while their perception of eating difficulty could vary based on their dental state at specific points in time.

Optimizing Coal Ash as a Sustainable Substitute of Cement and Aggregate in Structural Concrete

The manufacture of concrete for constructing the structures like highways, bridges, and buildings requires large amounts of cement and aggregates. This high concrete production depletes natural resources like sand and gravel for the construction industry. It also negatively impacts the environment due to cement usage. This study looked at using waste materials like coal bottom ash (CBA) and fly ash (FA) in concrete as substitutes for some of the typical aggregates and cement. The goal was to reduce the environmental impact and preserve natural resources. The study made concrete with regular Portland cement, sand, 10mm coarse aggregate, locally available CBA, and FA. 15% fly ash was selected as an optimal level from initial testing. The CBA was used to replace 0-35% of the fine aggregate sand. Test cubes and cylinders were made with different mixes. Compressive strength, tensile strength, carbonation, and sulfate attack tests were done after curing. Results showed 25% CBA improved the concrete’s mechanical performance. The compressive and tensile strengths increased but not above conventional concrete. This is because CBA needs more moisture for full hydration over longer curing times. Also, the concrete’s durability improved in terms of resistance to carbonation and sulfate attack.

Simulation-Based Performance Analysis of Impregnated Wood with Phase Change Material for Energy Efficient Timber Structures

Organic phase change materials (PCMs) offer a promising approach to improving the energy efficiency and sustainability of buildings. Impregnating wood with PCMs presents the opportunity for its application in building construction to reduce energy consumption for heating and cooling of indoor spaces. In this study, the process of solid wood impregnation with PCMs was conducted, along with the characterisation of their thermal properties. To define an optimal melting point and quantity to be incorporated into test cubes exposed outdoors for long term in Kuchl (Austria), a digital model was used to simulate beech and spruce that were impregnated with PCMs featuring two differing melting points. The results show that incorporating PCM into walls and floor can potentially reduce summer overheating by up to 48%. This effect is achieved using a building design that includes wood impregnated with PCM with a lower melting point of around 21°C. However, the building design and use of the employed PCMs do not reduce energy consumption for heating during winter. The results show that the performance is strongly dependent on the melting point of the PCM and its quantity in the building. These findings contribute to improving the design of the experimental test cube with impregnated wood and highlight the challenges.

EXPERIMENTAL STUDY OF SAMPLES MANUFACTURED FROM CRUSHED POLYMER WASTE ON A 3D PRINTER WITH A SCREW EXTRUDER

The article conducts an experimental study of samples made from crushed polymer waste on a 3D printer with a screw extruder. General information about the experimental study is given. An analysis of literary sources on the study of mechanical properties of products manufactured by FDM technology on 3D printers was carried out. Two 3D printers were chosen for the production of experimental prototypes, one of which prints with filament, the other with granules or crushed polymer waste. The equipment for determining the accuracy of printed samples has been selected. The measuring part of the tearing machine for taking tensile diagrams of polymer samples has been improved. A strain gauge for force measurement and an optical encoder for displacement measurement are installed in it. A digital electronic system for data collection from sensors based on the Arduino Uno microcontroller was developed. Software for experimental data processing was created. The general view of the experimental setup is given. It is proposed to use uniaxial tension to evaluate the mechanical characteristics of the test samples printed on a 3D printer. Current international standards for tensile testing of plastics are described. To determine the mechanical tensile characteristics, samples in the shape of a blade were made from polymer materials ABS and TPU. The parameters for printing test samples made from these materials are set. With the use of the developed installation, the failure diagrams of samples (blades) made of crushed polymer waste and filament of ABS and TPU plastics with different amounts of internal filling were obtained. In the form of tables, the values of the mechanical characteristics of the samples produced by the 3D printing method from ABS and TPU polymers with different internal filling obtained during the uniaxial tensile test are presented. A photo of the places of breakage of ABS plastic blades, taken using a digital camera, is given. An analysis of the structure of the samples was carried out on them. Experimental test samples were made using two 3D printers to determine the accuracy of 3D printing. Measurements were made in different planes of the test cube using a digital electronic caliper. The obtained results were compared with the created model. Ways to improve print accuracy are described.

Electric Sail Mission Expeditor, ESME: Software Architecture and Initial ESTCube Lunar Cubesat E-Sail Experiment Design

The electric solar wind sail, or E-sail, is a novel deep space propulsion concept which has not been demonstrated in space yet. While the solar wind is the authentic operational environment of the electric sail, its fundamentals can be demonstrated in the ionosphere where the E-sail can be used as a plasma brake for deorbiting. Two missions to be launched in 2023, Foresail-1p and ESTCube-2, will attempt to demonstrate Coulomb drag propulsion (an umbrella term for the E-sail and plasma brake) in low Earth orbit. This paper presents the next step of bringing the E-sail to deep space—we provide the initial modelling and trajectory analysis of demonstrating the E-sail in solar wind. The preliminary analysis assumes a six-unit cubesat being inserted in the lunar orbit where it deploys several hundred meters of the E-sail tether and charges the tether at 10–20 kV. The spacecraft will experience acceleration due to the solar wind particles being deflected by the electrostatic sheath around the charged tether. The paper includes two new concepts: the software architecture of a new mission design tool, the Electric Sail Mission Expeditor (ESME), and the initial E-sail experiment design for the lunar orbit. Our solar-wind simulation places the Electric Sail Test Cube (ESTCube) lunar cubesat with the E-sail tether in average solar wind conditions and we estimate a force of 1.51×10−4 N produced by the Coulomb drag on a 2 km tether charged to 20 kV. Our trajectory analysis takes the 15 kg cubesat from the lunar back to the Earth orbit in under three years assuming a 2 km long tether and 20 kV. The results of this paper are used to set scientific requirements for the conceptional ESTCube lunar nanospacecraft mission design to be published subsequently in the Special Issue “Advances in CubeSat Sails and Tethers”.

Microfluidic silicon interposer for thermal management of GaN device integration

With the popularity of the third generation semiconductor applications, silicon-based hetero-integration is driven to be applied massively by the miniaturization of microsystems and modules. The system-level power has a sharp increase in recent years, and consequently, hotspot thermal management is being increasingly concerned. A high-power GaN device with chip heat fluxes > 500 W/cm2 and hotspot heat fluxes > 30 kW/cm2 is implemented in this work to study extremely uneven hotspot cooling for silicon-based hetero-integration. A customized microjet silicon interposer (SI) is designed and fabricated based on the on-chip hotspot distribution, and another common microchannel SI in similar sizes is prepared for comparison. The GaN device is integrated on SI and micro-assembled in a test cube. The measurement results demonstrate that the maximum junction temperature of the GaN device on microjet SI is down to 150.3 ℃ at 70 ℃ ambient temperature with a pressure drop of 231.9 kPa. The overall thermal resistance (TR) of the test vehicle with microjet cooling has a 7.11 ∼ 7.72 % reduction and its heat transfer coefficient (HTC) increases by 12.3 ∼ 28.3 % compared to that with microchannel cooling with the pumping power of 0.5 ∼ 1.5 W. The material properties of the GaN chip and SI are extracted from the measurement results and then used in the analysis of the thermal and hydraulic properties of both microfluidic SIs numerically. Their cooling performance and efficiency are evaluated and compared based on the performance evaluation criteria (PEC), field synergy number and entropy generation rate. According to the evaluation results, while the PEC of microjet and microchannel SIs increases with the pumping power, the microjet SI can contribute to the enhancement of the synergetic relationship between the flow and temperature fields and reduction of total irreversibility in the heat transfer process compared to the microchannel SI in pursuit of low overall TR. The field synergy number improves by 90.40 % and the argument entropy generation rate is 0.376 when the overall TR is 1.35 K/W. The findings can provide valuable references for hotspot thermal management in silicon-based hetero-integration.

Numerical model of cumulative damage evolution of offshore wind turbine grouted connection under cyclic axial load

GCs in OWTs are exposed to fatigue loads that can lead to damage of the grout before ultimate limit state is reached. A uniaxial and fatigue compression test of high strength grout material were carried out to obtain the compressive strength, failure mode, fatigue life and load-displacement relationship of test cubes. A uniaxial and fatigue tests were carried out on GCs specimens to study the damage evolution of the GCs. The fatigue test on GC was done by applying six incremental amplitude cyclic load ranges of 30%–80% of ultimate load on the GC. The scalar damage degradation parameter (SDEG) from the result of the numerical simulation was used to estimate a damage index which measured the cumulative damage evolution. The cumulative damage evolutions were influenced by the cyclic load amplitude. The larger the load amplitude, the higher the damage index accumulated. The numerical simulation results compared with the DNV code method showed that the DNV code predicted lower damage values for fatigue loads ratio of up to 0.725 and predicted higher damage values beyond the 0.725 loads ratio for the GC. The proposed numerical model predicted the laboratory test results of the grout cube and the grouted connections.

Experimental investigation on Hybrid Fibre-Reinforced Concrete (HFRC) fracture toughness and impact resistance with partial replacement of nano-silica

This paper focuses on the compressive strength, fracture toughness and impact resistance of hybrid fibre-reinforced concrete. A total of 78 numbers of compressive strength test cubes, 24 numbers fracture Edge Notched Disc Bend (ENDB) specimens, and 20 numbers of impact disc specimens were constructed and tested. The replacement of Nano-silica was kept constant at 2% based on literature. Glass and steel fibres of 50 mm length were used with 1–4% by weight of cement content. Based on the obtained results, Steel Fibre (SF), Glass Fibre (GS) and Nano-Silica (NS) combinations gave better strength and performance in concrete. The observation made herein is that NS reduces the porosity of concrete as verified with the ultrasonic pulse velocity (UPV) test and microstructural studies including Scanning Electron Microscope (SEM) analysis. The results indicate that fibre combinations achieved better fracture toughness and high-impact resistance while maximum compressive strength was attained for 2% NS + 0.5% SF and 0.5% GF combinations.

Energy Efficiency of Concrete with Phase Change Materials

Nowadays, our society has the responsibility of reducing the energy consumed in the building sector. A promising technology to achieve this goal is the implementation of thermal energy storage (TES) solutions in buildings envelopes. Phase change materials (PCM) which act as a thermal buffer, take advantage of the melting temperature of the material to change its state, improving building energy efficiency. This work explores and investigates how with a cheap PCM material, such as surf wax, high impact thermal results are obtained. To check and verify this condition, two concrete specimens were prepared with treated PCM aggregate and two without the PCM. The four test cubes were placed in an oven and using thermal sensors, the data about the temperature evolution during the process of heating and cooling was collected for further analysis. The results between the PCM concrete samples and the samples without PCM were compared, verifying the promising performance in terms of energy impact.

Mechanical properties and flexural behaviour of reinforced concrete beams containing recycled concrete aggregate

Increasing waste recycling has become an essential process in the construction industry due to the environmental and economic advantages, such as minimizing waste in landfills, saving natural resources, and decreasing pollution. Crushing and sieving waste from standard compression test cubes is used to produce the recycled concrete aggregate (RCA). A set of standard concrete cylinders, cubes, and beam specimens were made by utilizing coarse aggregate replacement ratios of 0%, 30%, 50% and 70%. At the day 28 stage, the specimens were tested to determine compressive strength, stress–strain relationship, splitting tensile strength, and flexural strength. In addition, four reinforced concrete (RC) beams were cast and tested under a four-point load to evaluate the flexural behaviour of RC beams with partial replacement of the natural aggregate with RCA. One was a natural aggregate (NA) control beam, while the others had varying RCA ratios (30%, 50% and 70%). The results show that the compressive strength of RCA concrete with the replacement by 30%, 50% and 70% decreased by 9.10%, 18.88% and 22.57% respectively, in comparison to the compressive strength of normal concrete (NC). The RCA concrete showed a high strain capacity, which indicated high ductility. The maximum RCA type strains ranged from 0.0056 to 0.0072. Concrete flexural strength showed a slight decrease in comparison to NC (18.83% decrease), where the tensile strength showed a 10.61% decrease in comparison to NC. As for RC beams, the load-carrying capacity decreased by 10.5% with increases in the replacement ratio.

The effects of laser wire directed energy deposition processing parameters on the properties of 309L stainless steel

Laser directed energy deposition technology using 309L welding wire feedstock was investigated in this research work. The aim of the study was to determine the effect of laser power and scanning speed on the microstructure and hardness of the 309L austenitic stainless steel. The travel speed and the laser power were varied from 350 mm/min to 650 mm/min, and from 700W to 1100W, respectively. The general microstructure of the test cubes was that of ferrite dendrites in austenitic matrix. The test samples fabricated at laser power between 700W and 900W showed lack of fusion. However, samples that were manufactured at laser power between 1000W and 1100W were of good quality and did not show any defects. The micro hardness ranged between 188HV0.1 to 211HV0.1.

Semi-solid wire-feed additive manufacturing of AlSi7Mg by direct induction heating

• Demonstration of an induction heating based additive manufacturing process. • The novel process enables high speed additive manufacturing with build rates of around 20 mm 3 /s (0.054 g/s). • Adaptation of induction power during the process allows multilayer specimen fabrication. • Defects in the novel process are analysed for the first time using µCT to pave the way for their future prevention. In this study, a novel process is presented in which direct induction heating with frequencies in the MHz range is used for the wire-feed additive manufacturing of the alloy AlSi7Mg. The high frequency of 1.5 MHz enables processing of 1.2 mm diameter wires without the need for indirect heating via a nozzle. The feasibility of the process is proven by the experimental identification of a proper process window regarding the influential parameters such as the distance between inductor and substrate, induction power and wire feed rate for the fabrication of single layers. Furthermore, a strategy for the successful fabrication of multi-layered cubes is developed. The microstructure of the cubes exhibits a characteristic variation along the build direction. Micro-computed tomography is used to reveal defects like lack of fusion and spherical pores in test cubes. The presented results are used to derive possible process improvements, which will allow the novel process to be used as a fast and powder-free alternative metal additive manufacturing route in future.

EFFECT OF TREATED WASTEWATER ON PROPERTIES OF CONCRETE

By introducing innovative strategies and methodologies, the modern world is focusing on asset conditioning, sustainability, and recycling. In order to assess the strength of concrete constructed with treated waste water, an experimental investigation was done. Before filling the mould, tests are performed on the cement paste. The curing time for the test cubes was 3, 7, and 28 days. The compressive and tensile strength of hardened cement cubes were measured after curing. The compressive and tensile strengths of cement cubes made using treated waste water were higher than those of cubes made with regular water . Following the cement tests, the concrete paste was applied to the moulds, which were subsequently tested after 7 days, 14 days, and 28 days of curing. The compressive strength test was calculated for the concrete cubes. The results revealed that the concrete constructed using treated sewage water had higher strength than regular water. So as per the results it can be concluded that the treated sewage water can be used for preparation of cement mortar and cement concrete. Keywords - Normal water, Treated Waste Water, Cement Cubes, Concrete Cubes, Coagulants.

Effect of cartoon viewing habits on developmental skills and attention span of preschool children

Background: Mass media has an important role in the development of behaviour of children as they are exposed to it at very young age itself. Computers, television, video games and other entertainment media have become a part of their day-to-day life. The present study aimed at identification of the effect of cartoon viewing habits on developmental skills and attention span of preschool children.Methods: The correlational research study was conducted on consecutively selected 200 preschool children from selected schools of Calicut district. A semi-structured questionnaire was used to identify the cartoon viewing habits of children and four tests (colour cancellation test, number cancellation test, colour trails test and Knox cube test) were used to detect the attention span and Vineland social maturity scale was used to detect the developmental skills. Through individual interview data from 200 preschool children and their parents were collected during a period of 6 weeks after validating the tools and the data analysed using descriptive and inferential statistics.Results: Children who watched fewer cartoons have more social quotient (98%). Developmental skills are more in younger children (96%). Cartoon viewing habits have significant association with age, gender, birth order, number of siblings, and the class of study. Significant relationship between cartoon viewing habits and developmental skills.Conclusions: The study concluded that to assess the impacts of cartoon viewing habits on developmental skills and attention span of preschool children revealed that increased duration of cartoon viewing can have detrimental effect on the attention span and developmental skills of preschool children.

Experimental analysis of parameters for AlSi10Mg powders from different manufacturers in selective laser melting

Customer expectations are increasing, especially with regard to the individualization of products, in which additive manufacturing is described as a disruptive technology. With a view to using the technology in a series application, extensive knowledge of the starting material, the powder, is necessary. In this article, AlSi10Mg in powder form (grain size range: 15–70 µm), which is used for the selective laser melting process, is analysed on the basis of various investigations. A distinction is made from other researchers, as a total of six powders of the same specification but from different manufacturers were used. An investigation of the relative humidity of the powders in the as-delivered condition was carried out using a moisture meter. It could be shown that the moisture lies between 5% and 15% and that the moisture can be reduced by about half by using dry bags. A qualitative examination with a scanning electron microscopy showed that the morphology and size distribution differ. Not only partially round, but also very misshapen particles and particles with and without adhesions are present. The flowability was determined with a calibrated Hall flowmeter. It was found that a lower proportion of fine particles in the powder lead to a more uniform flowability. In the investigation, a distinction was made between powder in the as-received state and dried powder. The particle size distribution was determined with a laser diffraction method and evaluated according to the Mie theory. To be able to carry out porosity analyses on the basis of micrographs, test cubes with the dimensions (10 × 10 × 10 mm3) were used. The parameters scanning speed (400–600 mm/s), hatch spacing (0.19–0.29 mm), and laser power (220–320 W) were varied. The results vary between 0.12% and 5.46% porosity. To combine the results, a pairwise comparison and a use-value analysis were carried out. Overall, the differences in the powders of the different manufacturers were found to be small, so that a recommendation was made for the most economical powder.

Deep learning for automated seismic facies classification

Several published solutions exist for the automatization of seismic facies labeling. We suggest an approach that applies tools from deep learning and semantic image segmentation, such as specific UNet-based neural network structure, total variation (TV) loss, pseudolabels, as well as domain-specific attributes and a novel image-warping augmentation technique. We use a patch-based training and prediction approach, and at the prediction stage, the facies labels for the test cube are collected with the patch overlap and with the averaging of the predictions. When applied to two open-source labeled seismic cubes, the algorithm demonstrates superior performance compared with the published results with regard to several metrics computed, such as accuracy, intersection-over-union, and F1 score. We compare the model predictions with and without the domain-specific augmentation and the pseudolabel approach with the metrics suggesting that the augmentation and the pseudolabels provide an increase in the model’s performance. Our method provides smoother labels due to the use of TV loss and pseudolabels, which is proved by the visual observation of the predictions of the final model in comparison with the baseline raw UNet model results.

An experimental study on strength characteristics of replacement of fine aggregate with stone dust and coarse aggregate with demolished concrete waste

The report presents a comparative examination of the experimental results of the characteristics of fresh and cured concrete with various natural with recycled coarse and fine aggregate replacement ratios. Crushing leftover concrete from laboratory test cubes and precast concrete columns yielded recycled coarse aggregate. Stone dust was used in place of recycled fine aggregate. One of the most significant components of a reinforced structural part is concrete. Concrete has an inextricable influence on reinforced concrete constructions. Concrete that isn't strong enough puts the entire structure in harm. Many structures nowadays fail as a result of a lack of strength. The mechanical properties of concrete changed by stone dust as a fine aggregate replacement material are investigated in this work. A comparative analysis of the experimental results of the properties of fresh and hardened concrete with different replacement ratios of natural with recycled coarse and fine aggregate are presented in the paper. Recycled coarse aggregate was made by crushing the waste concrete of laboratory test cubes and precast concrete columns. Recycled fine aggregate was replaced by stone dust. Concrete is one of the most important components in reinforced structural member. In reinforced concrete structures concrete have some inseparable influence. Lacking in concrete strength endanger the whole structure. Now a day it is seen that many structures fails due to lack of strength. In this paper investigate experiment is reported on the mechanical properties of concrete modified by stone dust as replacing material of fine aggregate and demolished concrete waste as replacing material of coarse aggregate and a study is conductto determine the engineering properties of compressive strength, tensile strength, flexural strength and water absorption capacity of partially replacement of natural sand and natural aggregate. In recent days the demand of river sand is increasing due to its lesser availability. Hence the practice of partially replacing river sand with stone dust is taking a tremendous growth. Due to critical stage of natural aggregate the availability of demolished concrete as recycled aggregate. Using discarded concrete as recycled aggregate conserves natural aggregate, lowers landfill impact, reduces energy use, and potentially saves money. The materials of the future are recycled aggregate. Stone dust and destroyed concrete waste were used to replace 25 percent, 50 percent, 75 percent, and 100 percent of fine and coarse aggregate, respectively. After a 28-day curing period, concrete samples (cubes, cylinders, and beams) are cast and evaluated. To produce the effect on mortar, several members were built utilising the above percentage. Modified concrete is compared to regular concrete in terms of strength. The strength parameters of concrete employing stone dust as fine aggregate and demolished concrete debris as coarse aggregate are observed to increase in compressive strength, flexural strength, and tensile strength. It was discovered that the concrete may be used as structural members in buildings and other structures.

An Investigation on Effects of Sisal Fiber Reinforced Concrete on Concrete Properties

One of the additional materials for sustainability and strength of concrete is Fiber Reinforced Concrete. Hence, the researcher is attempting to use sisal fiber as an effective and sustainable additive to produce good quality fiber reinforced concrete. This study aimed to examine the effects sisal fiber on the compressive and flexural strength of concrete. As well as it recommends the optimum percentage of sisal fiber percentage. Sisal fibers were brushed, lined up, and cut to obtain a 5cm length of the fiber. To produce a well-mixed fresh concrete, the fiber was added after mixing all concrete ingredients. The compressive strength was tested at the ages of 7, 14, and 28 days of curing. Flexural strength was tested at ages 7 and 28 days curing. A total 45 of 150 x 150 x 150mm concrete test cubes and 30 of 50mm x 100mm x 100mm beams were cast using a mix proportion of 1:1.93:3, with water-cement ratio of 0.5. The results showed that the compressive and flexural strength increased as the sisal fiber percentage increased up to 1.5%. The optimum values of compressive and flexural strength come from concrete containing 1.5% sisal fiber. Based on the test results, the compressive strength at 0.5%, 1.0%, and 1.5% gained 4.53%, 16.56%, and 29.69% of the average compressive strength respectively. At 2% addition of fiber, concrete lost 35.31% of strength at 28 days curing. The flexural strength at 0.5%, 1.0%, and 1.5% sisal fiber gained 9.23%, 12.1% and 9% of strength respectively, while at 2% the addition of sisal fibber lost 15% of strength at 28 days curing. Therefore, the addition of sisal plant fiber increased both compressive and flexural strength up to 1.5% fiber by weight of cement compared to the control group of concrete 1.5% of sisal fiber is recommended.

Durability properties of self compacting concrete partial replacement of fine aggregate with waste crushed glass

This research work presents the durability properties of self-compacting concrete partial substitution of sand with waste crushed glass. In SCC cement was replaced with Fly-ash (15%), Alccofine (20%) by weight of cementitious material. These binder proportions are fixed for all mixes. Waste crushed glass has sufficient amount of amorphous silica content which is easily substituted to fine aggregate in SCC. Proportions are taken to replace the fine aggregate with waste crushed glass was 0%, 10%, 20%, 30% and 40% by weight of sand in mix. Grade of the concrete prepared was M70 and W/C was taken as 0.3. In present research work acid attack test and half-cell potential were carried out. For Acid attack test cube specimens of size (100 mm × 100 mm × 100 mm) were casted and cured for 90 days, for half-cell potential test cylinders (200 mm × 100 mm) were casted and cured for 90 days. In acid attack test 5% of hydrochloric acid and sulfuric acid were taken for testing. The results of normal concrete and concrete with waste crushed glass are compared. Test results showing better performance with waste crushed glass in Sulfuric acid and Hydrochloric acid. With 40% waste crushed glass, specimens immersed in Sulfuric acid, weight loss and strength loss are 3.8% and 4.85% respectively by weight before immersed in Sulfuric acid. With 40% waste crushed glass, specimens immersed in Hydrochloric acid weight loss and strength loss are 2.56% and 6.08% respectively by weight before immersed in Hydrochloric acid. Half-cell potential test values are showing increasing the glass content corrosion of steel was decreasing.

Mix Design Recycled Aggregate Pervious Concrete and the Influence on Pavement Property

This paper prepared recycled aggregate pervious concrete by replacing natural aggregate with 100% volume of waste concrete. We carried out experiments to study the influences of strength grade and target porosity of waste recycled aggregate concrete on the recycled one’s compressive strength and permeability coefficient. Then, the optimal proportion meeting the requirements of pervious concrete pavement is obtained, which is expected to be applied to the pavement with low strength requirement and water permeability. The test results of the compressive strength and permeability coefficient of 28-day test cubes show that, considering both the compressive strength and permeability, the best proportion is as follows: the strength grade of recycled aggregate is C20 + C30, the mix proportion of aggregate is 50%, the target porosity is 15%, the water-cement ratio is 0.3, the recycled aggregate is composed of 50% recycled aggregate with a particle size of 4.75-9.5 mm and 50% that of 9.5-19 mm, and the optimal mix proportion of recycled aggregate pervious concrete (kg/m3) is: m (recycled aggregate): m (cement): m (water) = 1357.04:564.94:169.88. The compressive strength and the permeability coefficient of recycled aggregate pervious concrete based on this mix proportion are 25.07 Mpa and 6.23 mm/s, respectively, which are in line with the provisions of Technical Specification for Application of Recycled Aggregate Pervious Concrete (CJJ/T 253-2016) and can be used for pavement. The study results can provide a reference for the promotion and application of recycled aggregate pervious concrete in the pavement.