Plastic Tensile Strength Research Articles

Effect of clay content on plastic shrinkage cracking of cementitious materials

Clay minerals in manufactured sand exacerbate plastic shrinkage cracking of cementitious materials. The impact of clay content on plastic shrinkage cracking and the underlying mechanism were comprehensively investigated. The results indicate that clay considerably mitigates the plastic settlement while significantly aggravates the plastic shrinkage, triggering more severe cracking. Water absorption of clay substantially lowers the permeability of mortars, which accounts for the reduction in bleeding, evaporation and plastic settlement. The intensified plastic shrinkage can be attributed to the accelerated build-up of capillary pressure and the self-contraction of clay. Furthermore, the critical cause of the more severe cracking with higher clay content is the rapid increase of plastic shrinkage and the reduction in plastic tensile strength.

Research on Early Warning System for Plastic Shrinkage Cracking of Cement Mortar Based on Constitutive Equations

Aiming at the plastic shrinkage cracking of cement mortar, the constitutive equations of it in laboratory were established by testing plastic tensile strength, plastic capillary shrinkage stress and water loss evaporation rate of mortar under different composition parameters, environmental parameters, initial structural parameters and constraints condition parameters. And the early warning system of it was explored. The results showed that the seven-element constitutive equation of plain mortar and the nine-element constitutive equation of mortar with polyvinyl alcohol (PVA) fiber can effectively predict the plastic shrinkage cracking state of mortar outdoors. An early warning system for it was initially established.

Research on influence of admixtures to the plastic shrinkage cracking of mortar

In this paper, the influence of admixture on plastic shrinkage cracking was studied. The results show that the plastic tensile strength increases while plastic shrinkage stress decreases as the content of air-entraining agent grows to 150×10-6 wt.%, and the anti-cracking index increases as a whole. Water reducing agent, water retaining agent, and shrinkage reducing agent all have the effect of improving plastic shrinkage cracking of fresh cement mortar. The constitutive relations between the admixtures content and anti-cracking index have been built.

The Effect of Stocking Temperature on Biodegradable Plastic Characteristics of Suweg Tuber (Amorphophallus campanulatus) with Addition of Glycerol and CMC (Carboxy Methyl Cellulose)

Research that uses Suweg tubers as the basic material for making biodegradable plastics has been carried out.. This research aims to determine the effect of stirring temperature on the characteristics of biodegradable plastic. Suweg tuber starch preparation is done as the manufacture of biodegradable plastic. Manufacture of biodegradable plastics made by mixing suweg tuber starch, glycerol, and acetic acid, as well as the CMC (Carboxy Methyl Cellulose). The manufacture of biodegradable plastic is carried out in two stages, namely stirring temperature variations (80⁰C, 85⁰C, 90⁰C, and 95⁰C) and the addition of CMC (Carboxy Methyl Cellulose). Tests carried out include FTIR test, mechanical test and biodegradation test. FTIR test is carried out to determine the functional groups contained in plasticThe test of plastic mechanical properties was carried out to determine the mechanical properties of plastics, such as tensile strength, elongation, and thickness. Biodegradation tests are carried out on the ground to determine the level of plastic degradation while in the environment. The results showed that the effect of temperature affected the mechanical properties of biodegradable plastic produced. Mechanical tests of stirring temperature variations with the addition of glycerol resulted in tensile strength, elongation, and thickness values of 80⁰C at 10.43 MPa; 2.08%; 85⁰C at 28.52 MPa; 1.60%, 90⁰C of 29.76 MPa; 2.18%, and 95⁰C of 32.49 MPa; 2.05%. These results can be seen that the largest biodegradable plastic tensile strength is found in temperature variations of 95⁰C, with a tensile strength of 32.49 MPa elongation 2.05%, and a thickness of 0.12 mm.. Mechanical properties test of temperature variation with the addition of glycerol and CMC resulted in the value of tensile strength, elongation, and temperature thickness of 80⁰C at 18.68 Mpa; 12.22%, 85⁰C equal to 14.69 MPa; 9.16%, 90⁰C of 16.71 MPa; 14.72%, 95⁰C of 13.94 MPa; 14.166%. These results can be seen that the largest biodegradable plastic tensile strength is found at 80⁰C temperature variations of 18.68 MPa, 12.22% elongation, 0.14 mm thickness. FTIR test, the biodegradable plastic produced, it is known that the plastic group produced is like CH, ester or ether. Plastic bio degradation test on soil, plastic with a temperature variation of 95⁰C has been degraded after 8 days, while plastic with the addition of CMC is degraded faster, for 7 days.

SYNTHESIS OF CHITOSAN-FILM COMPOSITE TiO2 USING SORBITOL AS PLASTICIZER

<p>The synthesis of chitosan–TiO<sub>2</sub> film composite using sorbitol as plasticizer has been conducted. This research aims to develop environmental friendly plastic material which is safe for health due to the use of biodegradable chitosan - TiO<sub>2 </sub>that can block UV rays and therefore, maintain the quality of product from damage caused by UV rays. The anatase phase TiO<sub>2</sub> nanocrystal was synthesized in chitosan matrix at room temperature and aging process. The solution was then added and blended in sorbitol for 24 hours to obtain homogeneous solution. The composite film was formed by coating method on a plate substrate, followed by drying. The characterization of film composite by XRD, TEM and FTIR showed the forming of anatase phase TiO<sub>2</sub> nanocrystal that dispersed in chitosan matrix and formed the hydrogen bond. Meanwhile, from the physical properties characterization it was observed that the use of sorbitol as plasticizer had improved the plasticity tensile strength and elongation of the composite film. However, the excess sorbitol reduced the elasticity, tensile strength and elongation of the plastic. The best quality of plasticity obtained from film composite added by 3 % of sorbitol.</p>

SYNTHESIS OF CHITOSAN-FILM COMPOSITE TiO2 USING SORBITOL AS PLASTICIZER

<p>The synthesis of chitosan–TiO<sub>2</sub> film composite using sorbitol as plasticizer has been conducted. This research aims to develop environmental friendly plastic material which is safe for health due to the use of biodegradable chitosan - TiO<sub>2 </sub>that can block UV rays and therefore, maintain the quality of product from damage caused by UV rays. The anatase phase TiO<sub>2</sub> nanocrystal was synthesized in chitosan matrix at room temperature and aging process. The solution was then added and blended in sorbitol for 24 hours to obtain homogeneous solution. The composite film was formed by coating method on a plate substrate, followed by drying. The characterization of film composite by XRD, TEM and FTIR showed the forming of anatase phase TiO<sub>2</sub> nanocrystal that dispersed in chitosan matrix and formed the hydrogen bond. Meanwhile, from the physical properties characterization it was observed that the use of sorbitol as plasticizer had improved the plasticity tensile strength and elongation of the composite film. However, the excess sorbitol reduced the elasticity, tensile strength and elongation of the plastic. The best quality of plasticity obtained from film composite added by 3 % of sorbitol.</p>

SYNTHESIS AND CHARACTERIZATION OF BIODEGRDABLE PLASTIC FROM CASAVA STARCH AND ALOE VERA EXTRACT WITH GLYCEROL PLASTICIZER

Synthesis and characterizations of Biodegradable Plastic made of Cassava Waste Starch, glycerol, acetic acid and Aloe vera extract has done. The aims of this research are to study the influence of addition of aloe vera extract in plastics mechanics properties, water vapor transmission rate and biodegradation. There are five main steps in this research, extraction of aloe vera, cassava starch preparation from cassava waste, preparations, characterization and biodegradability study of biodegradable plastic. The addition variations of aloe vera extract that used in this research are 0.01; 0.03; 0.05; 0.07 and 0.14 grams. Results showed that the addition of aloe Vera tends to increased biodegrable plastic thickness to 0.01 mm and elongation to 32.07%. However, biodegradable plastic tensile strength tends to decreased to 23.95 Mpa. Optimum tensile strength is 3.90 Mpa and elongation is 34.43%. Optimum water vapor transmission rate is 2.40 g/m2hours. Biodegradation study of biodegradable plastic showed that addition of aloe vera extract doesn’t significantly influence in plastic degradations.

Properties of Cracking Resistance of Cemfiber Reinforced Concrete

Polypropylene fiber is a new measure to prevent plastic cracks of concrete. Effects of the parameters, such as dosage and types of fibers, on the plastic cracks were studied systematically. The properties of cracking resistance of mortar, ordinary concrete and high performance concrete were investigated by using samples of two types in shape. The results show that: (1) polypropylene fibers may increase the cracking resistance of concrete further; (2) as smaller quantity of cement and higher quantity of aggregate as possible should be used to prevent concrete form cracking; (3) the main reason why polypropylene fibers increase cracking resistance of concrete is that they increase strain capacity of concrete at early age, decrease shrinkage strain, improve plastic tensile strength and decrease tensile stress of the capillary.

Effect of Longitudinal Splitting on Tensile Strength of Unidirectional Aramid Fiber Reinforced Plastics

An increase in aramid SVM (trademark of polyparaamidobenzimidazole fiber) content up to 85 vol. % leads to an increased tensile strength of the composite. An increase in fiber content, Vf, leads to a change of the fracture mode from fiber control at low Vf to matrix and matrix/interface dominated longitudinal splitting of the composite at high Vf. The correlation between transverse properties and longitudinal tensile strength of different aramid fiber reinforced plastics was investigated. Longitudinal splitting of the composite leads to a decrease in longitudinal tensile strength. Shear strength of the aramid fiber reinforced plastic possesses a low sensitivity to its resistance to longitudinal splitting. For this the transverse strength or interlaminar fracture toughness of the composite may be used. Matrix plasticization leads to an increase of aramid Terlon (trademark of poly paraphenelenterephthalamid) fiber reinforced plastic tensile strength due to suppression of longitudinal splitting.

Tensile strength of acrylic plastics (PPM) in the presence of a temperature gradient over the thickness of the material

Experimental values of the strength and deformation are presented for SO-95, SO-120, and SO-140 acrylic plastics (polymethyl methacrylate: plasticized, unplasticized, and copolymer) stressed in unaxial tension at v=10 mm/min, stationary temperature gradients of from 2.5 to 17.5 deg/mm over the thickness of the material, and a constant cold-face temperature of 25°C. The deformation properties under these conditions are described: in the presence of a temperature gradient the ultimate strains are higher than for a uniform temperature field at a temperature equal to the cold-face temperature, and the elongation at break falls as the hot-face temperature rises. The tensile strength of plastics with a temperature drop over the cross section can be approximately calculated from the mechanical characteristics obtained for a uniform temperature field.

Tensile strengths of glassy plastics with drilled holes and measurement of griffith parameters

AbstractThe tensile strengths of plastics with drilled holes can be analyzed by treating the hole as a nucleus in flaw generation. The analysis is accurate for hole diameters less than the inherent flaw size. Above this value the tensile strengths define a single curve when plotted on a reduced variable scale. Using the analysis in its linear range facilitates evaluation of the Griffith parameters. From such an application it was found that plasticizers markedly reduce the values of the Griffith parameters while affecting tensile strengths only slightly. Temperature has a similar effect.

Tensile Strength of Plastics: Effects of Flaws and Chain Relaxation

A theory for the tensile strength of amorphous plastics is presented. It extends a previous theory so as to include the effects of imperfections and chain relaxations. The result obtained shows that the time taken for a plastic to break, tc, under constant stress, F, is given by F=−Bln(tc)+C,where B and C are molecular constants. The experimental values found for these constants are shown to be consistent with their molecular interpretation. This extended theory shows that the effect of chain relaxations is the major time dependent factor as far as strength is concerned.

THE EFFECT OF FINE GRINDING ON AN INDURATED CLAY1

Fine grinding develops certain desired physical properties of a clay that has become hard by the pressure of the overlying stratas and the heat produced by this pressure. The fineness of grind produces in direct proportion an increase in the plasticity, plastic tensile strength, and shrinkage, and a decrease in the absorption and porosity. An indurated clay can be made to produce required properties by the proper fineness of grinding.