Drop Weight Method Research Articles

Determination of parameters generating the reference pressure in the primary level dynamic pressure measurement system based on the drop weight method

For some industries such as automotive, defence, aerospace, pharmaceutical manufacturing, dynamic pressure measurement is an important requirement. In a primary level dynamic pressure measurement system with a drop weight method, the dynamic pressure value is calculated using parameters such as the effective area value depending on the piston cylinder unit, the maximum acceleration value measured by a laser interferometer. On the other hand, the type of liquid used in the measuring head is another important factor affecting repeatability and providing ease of measurement. In this study, a new measurement head, piston and cylinders were designed, manufactured and the Taguchi method was used to accurately determine some parameters affecting the measurements in a dynamic primary pressure measurement system operating with the drop weight method. In the studies carried out, four pistons, four cylinders, four sampling frequency values and two liquid types were considered. By using the Taguchi method, the optimum parameters of the dynamic pressure measurement system with drop weight method were determined with only sixteen experiments instead of one hundred and twenty-eight.

(Digital Presentation) Experimental Results on the Determination of the Billiter Potential

The experimental effects at the Billiter potential are measured in narrow intervals of the equilibrium potentials (A, B). The Billiter potential + 0.475 V SHE [1-3] is confirmed by the following experimental results [4,5,7- 9]. The change in the direction of the current between a dropping mercury and a mercury bottom in solutions of redox systems Fe(CN)6 3 - - Fe(CN)6 4 - and quinone-hydroquinone at a given potential E equil . = + 475 V SHE has been established with exactness ± 1-2 mV [4, 5]. This result was confirmed in [6]. At E equil. > +0.475 V SHE, the current flows from a mercury bottom to dropping electrode and at E equil. < +0.475 V SHE - in the opposite direction. Electrocapillary curves have been found by drop-weight method in these solutions in narrow range E equil. ~+0.4 ÷+0.55 V SHE with a maximum at E equil. ~ + 0.475 V SHE [4].A self-recording galvanometer was used to record the reversal of the current between a mercury bottom and a dropping electrode in solutions of redox systems [7-9]. In a solution of quinone-hydroquinone redox system, a recorded positive current decreases exactly to zero at E = + 228 mV SCE (+ 475 mV SHE), and then a negative current increases with continuous dropping of mercury. E equil. changes by itself since an adsorbed quinone on mercury drops are removed from solution onto mercury bottom (A).The current reversal at E ~+ 0.22 ÷ + 0.23 V SCE (~+0.475 V SHE) has been recorded by a recorder between a mercury bottom and a dropping electrode in acidified Hg2(NO3)2 solutions with the addition of complexing agents (triethanolamine, sodium ethylenediaminetetraacetate, thiocarbamide, others) [7-9].The electrocapillary curves (ECC) have been measured by weight-drop method in these solutions (B; with sodium ethylenediaminetetraacetate). After passing the electrocapillary maximum for reversible Hg2 2+/ Hg electrode at E ~ + 0.22 ÷ + 0.23 V SCE, we have obtained an ascending branch of ECC of an ideally polarizable electrode at E equil. < ~+0.190 ÷ +0.210 V SCE. A registered second current reversal at these E equil. corresponds to the transition from a small descending branch of ECC of Hg2 2+/Hg electrode to an ascending branch of ECC of an ideally polarizable electrode. The electrocapillary maximum was also obtained using diluted acidified solutions of Hg2(NO3)2.An increase in a polarization resistance and a change in polarization capacitance have been detected when impedance measuring with reversible electrodes at Ee ~ +0.475 V SHE. These effects were also measured on mercury drops in the diluted 10-10 N solution of Hg2(NO3)2 + 0.1÷ 0.001 N KNO3 The increase in polarization resistance was explained by the achievement of chemical equilibrium of half-reactions at Ee quil. ~ +0.475 V SHE [6,7,16].Measurements by the immersion method with redox systems and solid electrodes of the second kind confirm the reversal of the current at E ~+ 475 V SHE. Submersible small solid electrodes must be absolutely clean and dry [5]. This method is under development.According to [8 - 10], Billiter potential corresponds to some electrode with zero chemical activity (transitional from metals to non-metals with the intermediate electron work function 5.19 eV). The same zero activity is obtained at chemical equilibrium of half-reactions when the sum of changes of chemical potentials of electrons and ions Δμion + Δμelectron = 0, and potential drops in double - electric layers are compensated. The components Δμion= 0 and Δμelectron≠ 0 correspond to potentials of zero charge Ep. z.c. For mercury, the electron work function is 4.52 eV and Δμelectron = 4.52 eV - 5.19 eV = - 0.67 eV. In order Δμion + Δμelectron = 0, Δμion should be equal + 0.67 eV. Indeed, if E p.z.c. = - 0.193 V SHE for mercury is changed by + 0.67 V we obtain the chemical equilibrium of half-reactions at ~ +0.475 V SHE. REFERENCES J.Billitzer, Methods for Determination of the Absolute Potentials, Trans. Amer. Electrochem. Soc., 1930,57, 351.The Encyclopedia of Electrochemistry, C.A. Hampel (ed.), (Reinhold,New York, NY) (1964).H.J.Oel, H Strelow,Z. Electrochem, 1954,58,665.A.I.Chernomorskii, Soviet Electrochemistry, 1981, 17, 874.A.I.Chernomorskii, Russian Journal of Physical Chemistry,1981, 55, p.206.Ya.I.Tur’yan, Redox Reactions and Potentials in Analytical Chemistry, Khimiya, Moscow, 1989.A.I. Chernomorskii,N.S.Polizan, Reports of Academy of Sciences of the Uzbekistan,1990, 6, 35.A.I.Chernomorskii, Thernodynamics of Electrodes, FAN, Tashkent, 1993.A.I.Chernomorskii, The Intermediate Electron Bond and Half-reactions, Scientific Resources, New York, 1999.A.I. Chernomorskii, Journal of The Electrochemical Society, 2021, 168,116514. Figure 1

The surface tension of Ga2O3 melt measured by a drop-weight method in an optical floating-zone furnace

The surface tension of Ga2O3 melt is successfully measured using a drop-weight method in an optical floating-zone furnace that we have developed. The method is verified to be feasible by measuring the surface tension value of TiO2 melt and then comparing it with values in previous reports determined by other methods. We find that the surface tension of Si-doped Ga2O3 melt increases with the decrease in the Si doping concentration and reaches 527.9 mN m−1 for pure Ga2O3 melt. The surface tension of the unintentionally doped Ga2O3 melt is also measured to be 519.3 mN m−1 in the presence of some common contaminants appearing in Czochralski and edge-defined film-fed growth methods, including Ir, Al, and Si.

Impact Test of Ultra-High Performance Concrete Slab with Basalt Fiber

In order to study the impact resistance performance of ultra-high performance concrete (UHPC) slab with basalt fiber, the experiment of six concrete slabs was conducted. The following factors were considered in this study: different basalt fiber types, steel mesh, and water-based epoxy mixture. The drop weight method was used, and the effect of various factors on the impact resistance performance of ultra-high performance concrete slab with basalt fiber were investigated in details. The test results showed that the basalt fiber could significantly increase the impact resistance of UHPC slab. The basalt fiber with a long length after cracking was more significant to improve the impact resistance performance of UHPC slab. The basalt fiber, steel mesh, and water-based epoxy can significantly improve the impact resistance and energy absorption capacity of UHPC slab. The ductility coefficient of UHPC slabs are less than 0.6.

Biodiesel fuel. part ii. thermophysical properties of systems participated in the process of obtaining biodiesel fuel using working media in the supercritical fluid state

THE PURPOSE. The purpose of the work was to systematize the results of the work of domestic and foreign authors on the thermophysical properties of media and substances involved in the process of obtaining biodiesel fuel. METHODS. To measure the isobaric heat capacity, the predominant use is given to the methods of heat-conducting and scanning calorimeters, the measurement of the thermal conductivity by the heated filament method. Kinematic and dynamic viscosities are measured, respectively, on standard glass viscometers at atmospheric pressure and by the drop weight method. RESULTS. The results of a study of a wide range of thermophysical properties of thermodynamic systems involved in the process of obtaining biodiesel fuel under supercritical fluid conditions are presented. Attention is paid to the density, isobaric heat capacity, thermal conductivity, dynamic and kinematic viscosity of both the feedstock and the resulting biodiesel fuel, presented in a wide range of temperature and pressure changes, including nearcritical, as well as taking into account the thermal effects caused by the dissolution and change in the structures of substances under the influence of fluid reagent. CONCLUSION. The presented data will be necessary at the stages of designing and scaling a particular technology for the production of biodiesel fuel, both on a laboratory scale and at an industrial level.

Research on Grinding Characteristics and Comparison of Particle-Size-Composition Prediction of Rich and Poor Ores

The particle size composition of grinding products will significantly affect the technical and economic indexes of subsequent separation operations. The polymetallic complex ores from Tongkeng and Gaofeng are selected as the research object in this paper. Through the JK drop-weight test, the batch grinding test, and the population-balance kinetic model of grinding with the Simulink platform, the grinding characteristics of the two types of ores and the particle-size-composition prediction methods of grinding products are studied. The results show that the impact-crushing capacity of Tongkeng ore and Gaofeng ore are “medium” grade and “soft” grade, respectively. The crushing resistance of Tongkeng ore increases with the decrease in particle size, and the crushing effect is more easily affected by particle size than that of Gaofeng ore. For the same ore, the accuracy order of the three methods is: PSO–BP method &gt; JK drop-weight method &gt; BIII method. For the same method, only the BIII method has higher accuracy in predicting Gaofeng ore than Tongkeng ore, and other methods have better accuracy in predicting Tongkeng ore than Gaofeng ore. The prediction accuracy of the BIII method is inferior to that of the JK drop-weight method and the PSO–BP method and is easily affected by the difference in mineral properties. The PSO–BP method has a high prediction accuracy and fast model operation speed, but the accuracy and speed of the iterative results are easily affected by parameters such as algorithm program weight and threshold. The parameter-solving process of each prediction method is based on different simplifications and assumptions. Therefore, appropriate hypothetical theoretical models should be selected according to different ore properties for practical application.

Shape approximation of sessile droplet by the equivalence between vertical capillary force and hydrostatic pressure

Liquids are widely employed in the investigations of wetting in the form of droplets, especially for superhydrophobic surfaces. An accurate approximation for the shape of sessile droplets is of significance for facilitating the studies of surface wetting. Inspired by the principle of the drop weight method, we derived the equivalent relationship between the vertical capillary force at the contact line and the hydrostatic pressure of a sessile droplet on horizontal substrates. On the basis of the force equivalence, a new model using elliptical arcs to approximate the profile of actual droplets is developed. In addition to predicting the droplet shape, the proposed model enables the inverse estimation of the physical parameters according to the characteristic sizes of the droplet profile. The estimation results accord well with the measurements within a wide range of droplet volumes, which fully demonstrates the validity and application potential of our model. Moreover, the force equivalence has been utilized to explain the volume difference of evaporative droplets falling through the superhydrophobic holes present on different grades of mesh substrates. It is anticipated that the newly proposed force-based model will contribute to the deep understanding of sessile droplet-related phenomena, such as the Cassie-Wenzel transition and nondestructive transfer.

Modelling and analysis of a hydraulic support prop under impact load

The prop is the most important part to ensure the proper functioning of hydraulic support. When the hydraulic support is impacted by the roof, the prop is prone to extrusion deformation, expansion, and even bursting. In order to study the stress on a doubly-telescopic hydraulic support prop under impact load, an impact simulation was carried out based on the drop weight method. First, the impact model of the hydraulic system of the prop was established in AMESim software and the dynamic response curves of the bottom and middle cylinder of the prop obtained. Then, according to the conservation of energy, the pressure formulaes in the hydraulic cylinder of the prop under impact load were derived and verified by the AMESim simulation results, and the maximum pressure on the inner surface of the hydraulic cylinder of the prop obtained. Lastly, the transient dynamic simulation of a hydraulic support prop was carried out in ANSYS Workbench software, and cloud diagrams of stress and deformation of the prop obtained using Workbench simulation. The AMESim simulation process describes the change in fluid pressure in the prop, and the pressure formulae can be used to estimate the internal pressure of the prop under impact load. The finite element analysis results show that the stress of the middle hydraulic cylinder is much greater than that on the bottom hydraulic cylinder under impact load, which can provide a reference for prop design.

A Study on the In-Plane Shear-after-Impact Properties of CFRP Composite Laminates.

Impact loading on carbon fiber reinforced polymer matrix (CFRP) composite laminates can result in a significant reduction in their residual properties, and the (ShAI) properties of the composite material are essential to obtain the material allowable values of the shear dominated composite structures. In order to obtain the ShAI properties of the composite material in pure shear stress at a coupon level, this study presents theoretical, experimental, and numerical methods and analysis work on the in-plane shear and ShAI properties of the composite laminates. Theoretically, a method of sizing the composite specimen loading in shear is developed through comparing the load values due to buckling and the material failure. Following this, both impact tests using the drop-weight method and ShAI tests using the picture frame test method are conducted, and the influences of the impact energies on the impact damage and the residual ShAI values are evaluated. Moreover, a progressive failure finite element model based on the Hashin’s failure criterion and the cohesive zone model is developed, and a two-step dynamic analysis method is performed to simulate the failure process of the composite laminates under impact loading and ShAI loading. It is found that the impact damage with the cut-off energy, 50 J, causes a 26.8% reduction in the residual strength and the residual effective shear failure strain is about 0.0132. The primary reason of the shear failure is the propagation of both the matrix tensile failure and interlaminar delamination. It can be concluded that the proposed theoretical, experimental, and numerical methods are promising factors to study the ShAI properties of the composite materials.

Experiments and Finite Element Simulations of Composite Laminates Following Low Velocity On-Edge Impact Damage.

Composites are widely used in aircraft structures that have free edges and are vulnerable to impact events during manufacturing and maintenance. On-edge impact may have a great contribution in terms of the compression strength loss of composites, but the influence remains unclear. This paper presents experiments and simulations of carbon-fiber-reinforced plastic (CFRP) materials with on-edge impact and compression after edge impact (CAEI). On-edge impact damage was introduced to the composite laminates through the drop weight method with 4, 6, 8 and 10 J impact energies, respectively. A special guide-rail-type fixture was used in the compression tests in which strain–force and load–displacement relationships were obtained. A continuous-step finite element model was proposed to simulate impact and compression. Continuum shell elements and Hashin failure criteria were used to simulate in-ply damage, and interlaminar damage was modelled by cohesive elements. The model was validated by correlating the experimental and numerical results. The investigation results revealed the relationships of the damage size and residual strength with the different impact energies. The crack length and delaminated area grow with the increase in impact energy. The residual compressive strength follows a downward trend with increasing impact energy.

Temperature influence on the NAPL-water interfacial area between 10 °C and 60 °C for trichloroethylene

Underground thermal energy storage (UTES) can contribute to renewable energy usability, especially in urban areas with the most demand and available infrastructure. But UTES may interact in those areas with non-aqueous phase liquids (NAPL) by increasing the temperature in storage formations. To determine temperature effects on NAPL dissolution rates into groundwater, the effective specific interfacial area (anw) between trichloroethylene (TCE) and water, as a function of temperature and TCE pore saturations, was calculated. The interfacial tension between the flushing solution and the NAPL, the adsorption coefficient and the retardation of a reactive tracer were determined by the drop weight method and interfacial tracer tests at 10 °C, 30 °C and 60 °C. From 10 to 60 °C anw increased by a factor of six to eight. Based on the results, a function to describe the anw between TCE and water was developed, which could improve numerical models on NAPL dissolution rates. The main mechanisms for the increase in anw are suggested to be NAPL blob migration on pore scale, and thermal-induced changes in wettability and in blob shape correlating with a temperature-induced decline in effective porosity of up to 32%. These results contribute to the understanding and predictability of UTES in contaminated aquifers, the general response of NAPL behavior on artificial increasing aquifer temperatures and the improvement of thermal and other groundwater remediation techniques.

A new EPOR/CD131 heteroreceptor agonist EP-11-1: a neuroprotective effect in experimental traumatic brain injury

Introduction: EP-11-1 (UEHLERALNSS) is a short-chain erythropoietin derivative without have erythropoietic activity. It was created by modifying a peptide mimicking the spatial structure of the erythropoietin a-helix B pHBSP. One of the promising directions of its administration is the correction of morphofunctional disorders that occur in traumatic brain injury (TBI).&#x0D; Materials and methods: The study was performed in 160 male Wistar rats, weighing 180–200 g.TBI was simulated using the drop-weight method. To assess the emerging morphofunctional disorders and a degree of their correction, we used the severity of neurological deficit, indicators of locomotor activity and exploration, a marker of brain injury S100B and morphological examination.&#x0D; Results and discussion: The combined administration of a new EPOR/CD131 heteroreceptor agonist EP-11-1 with citicoline and trimetazidine led to a more pronounced correction of the neurological deficit when compared not only to the group of the ”untreated” animals, but also to the groups of animals to which these drugs had been administered as monotherapy (p &lt; 0.05). The same tendency was also observed in the study of locomotor activity and exploration. A biochemical study showed that the administration of all three combinations led to a statistically significant (p &lt; 0.05) decrease in the S-100B concentration compared not only to the group of “untreated” animals, but also to the groups of animals to which these drugs had been administered as a monotherapy.&#x0D; Conclusion: The results of the conducted experiments prove the most pronounced positive dynamics in the combined administration of the new EPOR/CD131 heteroreceptor agonist EP-11-1with citicoline and trimetazidine.

Artificial neural network applications in fiber reinforced concrete

The presence of fiber in the concrete increases the mechanical properties of the concrete considerably. This paper presents the application of Artificial neural network to predict the compressive and impact strength of the concrete with varying percentage of glass fiber along with different combination of chemical admixtures in concrete such as super plasticiser, air entraining agent, accelerators, retarder and water proofing agent. In experimental part of research, the specimens were tested to failure in order to measure the compressive strength and impact strength by drop weight method. The compressive strength and impact strength of the Glass Fiber Reinforced Concrete (GFRC) with different combination of admixtures get increased to 12% and 90% respectively as compared with control specimen. The predicted strength was compared with the experimentally obtained compressive and impact strength of glass fiber reinforced concrete. The strength predicted by ANN is very close to the experimental results with minimal error.

Analysis of accuracy of burette in determination of surface tension of liquids and study of its variation with detachment time and inclination angle

A simple laboratory experiment to measure the surface tension of liquids has been proposed in this work, which is well suited for any undergraduate laboratory demonstration. Burette with modified Tate’s law has been found to return surface tension values as good as those obtained using Traube’s stalagmometer. Experimental data and error analysis show similar result accuracy. Also, a comparative study brings to notice the exactitude of drop weight method over drop number method, both from stalagmometer and burette. The rate of flow of 11–23 drops per minute has been found to be highly suitable for minimization of errors due to evaporation and satellite drop formation. Angular dependence of surface tension has been proposed numerically and validated for the respective case with the angle of 0° to deviate the least from literature value. The results obtained in this study are synchronous with the established theoretical understanding of the concept.

Impact Resistance of GGBS-Dolomite Geopolymer Concrete

Geopolymers are new alternative binders for cement in which polymerization gives strength to concrete. The present study highlights the development of geopolymer concrete from industrial by-products such as Ground Granulated Blast furnace Slag (GGBS) and dolomite. They are obtained from steel industries and rock crushing plants respectively. Standard mix design guidelines are not available for geopolymer concrete. The trial and error method was chosen for attaining a target compressive strength of 60 MPa. Impact strength plays an important role in structures like bridges, harbours, and barriers. The present paper investigates the impact resistance of GGBS dolomite geopolymer concrete using drop weight method. Procedures of ACI Committee 544 were used, and results were compared with that of cement concrete. Cylindrical specimens having 150 mm diameter and 50mm thickness were used. Maximum impact resistance was observed when GGBS and dolomite become 80:20, which is 42% more than GGBS geopolymer concrete without dolomite.

Power generation characteristics of 0.50(Ba0.7Ca0.3)TiO3–0.50Ba(Zr0.2Ti0.8)O3/PVDF nanocomposites under impact loading

Power generation characteristics of 0–3-type 0.50(Ba0.7Ca0.3)TiO3–0.50Ba(Zr0.2Ti0.8)O3/PVDF nanocomposites, prepared using a melt-mixing process, under impact loading have been presented in this paper. A solid-state reaction process was utilized to prepare lead-free nanoceramic powder of 0.50(Ba0.7Ca0.3)TiO3–0.50Ba(Zr0.2Ti0.8)O3 (BCZT50) which was then milled by high-energy ball milling technique. The BCZT50 as filler distribution in the PVDF matrix was checked from scanning electron microscope and the formation of BCZT50 and BCZT50/PVDF nanocomposites were ascertained by X-ray diffraction method. The free dielectric constant ( $$\varepsilon_{33}^{T}$$ ), loss tangent (tanδ), piezoelectric coefficient (d33), piezoelectric voltage constant (g33), shore hardness (D), and figure of merit (FoM) were observed to increase while that of applied mechanical force (F3) decreases with the increase in filler concentration. Studies of voltage responses of all the BCZT50/PVDF nanocomposites due to impact loading using drop weight method have been carried out. A marked increment in the contact voltage due to different heights (applied mechanical energy) of impact was noticed as the concentration of filler particles was increased from 0 to 25% in the BCZT50/PVDF nanocomposites. The contact voltage and generated energy increase, respectively, from 5.37 to 11.62 V and 0.53 nJ to 6.8 nJ with the increase in BCZT50 content from 0 to 25% at a height of impact = 21 cm. In addition, the low value of tanδ (~ 10–2), high values of d33, g33, D and FoM along with better voltage responses (proportional to the applied mechanical energy) foreshadowing the prospect of BCZT50/PVDF nanocomposites a better non-lead option for structural health monitoring, piezo-sensing/detection, and/or energy harvesting applications.

Impact Resistance For Ready Mix Concrete Plant Waste Concrete Aggregate

The investigation to learn about the effect resistance for Ready Mix Concrete plant waste utilized in new concrete substitute of Natural aggregate. In concrete trade natural aggregate with RMC plant waste of 7 days old waste concrete aggregate in 20% interval up to 100%. In the impact testing machine a drop weight was developed to govern impact resistance on Natural Aggregate concrete &amp; RMC plant waste aggregate concrete. In aspect ratio (l/d) as 60 conducted Impact test on NAC &amp; RMC waste. The samples of M40 strength of concrete. The Impact test conducted on samples as per ACI-544 committee method and verified by drop weight methods. RMC waste concrete aggregate exhibited with variation of different percentage test results of impact strength energy. The impact resistance significantly increases by additions of RMC plant waste concrete aggregate.

Review of experimental techniques for impact property of adhesive bonds

Assessing the impact property of the adhesives and the joints requires specific suitable experimental methods. Especially the most of the adhesives are sensitive to the strain rate that they must have to meet when a load is applied abruptly on the adhesive and adhesively bonded joints. In general, the impact tests of adhesive joints are usually divided into three ranges including low, medium and high velocity. Sometimes a body in hypervelocity collides with another one is faster than the sound velocity. This document aims to review the experimental methods that have been previously undertaken in this field. Discussed research topics include the impact test methods for the adhesive joints under low, medium, high and hypervelocity. The standard impact tests for adhesive joints (involving both bonded blocks and strips) are typically test methods with low-velocity and they are discussed. In the medium-velocity range, the applications of drop weight, inertia wheel, wedge falling, servohydraulic and pneumatic test methods are presented. In the high-velocity range, the advance of Split-Hopkinson bar as a special apparatus conceived to test materials is reported. The final section describes two practical applications of adhesive joints impacted under hypervelocity.

Impact response of laminated glass with varying interlayer materials

This study investigates the influence of the interlayer materials on the low velocity impact performance of laminated glass. By varying the impact velocity, with a drop-weight, the effect of impact energy levels (3, 5, 10 and 15 J) has been explored on the impact resistance of laminated glass and the failure mechanisms have been assessed. The four interlayer materials investigated were: SGP–Ionoplast as employed in Sentry Glas® Plus, TPU-Thermoplastic polyurethane, PVB-Polyvinyl butyral and a TPU/SGP/TPU hybrid interlayer. The drop weight method has been employed to obtain the energy dissipation, loading and deformation of the laminated glass. The low velocity impact results indicate that both the type of the interlayer materials and the impact energy have great influence on the impact performance of the laminated glass. The laminated glass with TPU and PVB interlayer exhibited better impact resistance than the laminated glass with SGP and TPU/SGP/TPU hybrid interlayer, when impacted at energies of 3 and 5 J (corresponding to impact velocities of 1.71 and 2.21 ms−1 respectively). However, the laminated glass with SGP and TPU/SGP/TPU hybrid interlayers has better load carrying capacity and better anti-deformation property than the TPU and PVB interlayers at the higher impact energies of 10 and 15 J (impact velocities of 3.13 and 3.83 ms−1 respectively). The results are thought to be attributed to the differences in the viscoelastic properties of the interlayer materials with strain rates.

Impact strength enhancement of banana fibre reinforced lightweight self-compacting concrete

The research work was conducted to evaluate the potential enhancement of impact strength due to the addition of banana fibre in structural lightweight self-compacting concrete (LWSCC). The coconut shell was substituted instead of coarse aggregate partially to develop the lightweight concrete. The 28 and 90 days cured LWSCC specimens of M30, M40 and M50 grade was used in this study. The mix proportion of LWSCC was designed as ternary blended with rice husk ash (RHA) and micro silica (MS). In order to improve the impact strength of LWSCC, the banana fibres are supplemented in concrete at 0.25, 0.5, 0.75, 1.0, 1.25 and 1.5% by volume of concrete. The impact strength of LWSCC was calculated by drop weight method in accordance with ACI committee 544 procedure. The performance of LWSCC on the impact strength was examined along with compressive strength and further developed the correlation among the compressive and impact strength of LWSCC. The results showed that there is no undesirable effect on the self-compatibility because of the addition of banana fibre and had shown the significant improvement in compressive strength. The additions of 1.25% banana fibres improve impact strength of LWSCC.