Unplasticized Polyvinyl Chloride Pipes Research Articles

Decolourization of azo Lanasyn Navy M-DNL dye by Trichothecium roseum toward green mycoremediation

The treatment of azo dye effluent from the dyeing process, as well as the sustainable development of the environment, can all be achieved through the use of green mycoremediation. In this in vitro study, Trichothecium roseum was isolated by the sedimentation technique from the environment of an unplasticized polyvinyl chloride pipe manufacturing plant and used to decolourize and optimise the biosorption percentage of Azo Lanasyn Navy M-DNL dye. T. roseum was also used to test the decolourization percentage of the dyes Lanasyn Navy M-DNL, Isolan Black 2S-LDN, and Isolan Yellow 2S-GLN. The outcomes showed that Lanasyn Navy M-DNL dye has the highest decolourization percentage (94%). Lanasyn Navy M-DNL dye was also found to be adsorbed onto the surface of T. roseum using scan electron microscopy and Fourier-transform infrared spectroscopy investigations. Under ideal optimisation parameters, the biosorption percentage of Lanasyn Navy M-DNL dye by beads of immobilised T. roseum cells was 96%, 97%, 96%, 97%, and 96%, respectively, for beads number 60, fresh weight 1 g, incubation temperature 25 °C, pH 6, dye concentrations 10 mg/l, and sucrose concentrations 10 g/l. Langmuir and Freundlich adsorption isotherms show good agreement between the Freundlich adsorption isotherm model and the adsorption process. Also, the elution cycle was found to be effective enough to be employed for five cycles using sixty beads of immobilised T. roseum cells. The current study suggests that T. roseum is an influencer of Lanasyn Navy M-DNL dye biosorption to create a successful green strategy for handling Lanasyn Navy M-DNL dye-contaminated effluents.

Fundamental Investigation of Various Factors Affecting the Occurrence of Solvent Cracking for Unplasticized Poly Vinyl Chloride Pipes in Building Equipment

We investigated the occurrence of solvent cracking in unplasticized polyvinyl chloride pipes using test materials prepared by conventional methods. We confirmed that voids were formed on the inner surface of the pipe at a holding time of 2 weeks under conditions of room temperature (298 K), 1.0 g of applied adhesive, and 4 N/m U-band tightening torque. The voids formed linearly in the circumferential direction at regions in contact with the U-band and linearly in the axial direction at regions not in contact. Environmental agents of tetrahydrofuran (THF), 2-butane, and cyclohexanone were detected during analysis of void regions on the inner surface of the pipe and residual gas in the pipe. The results suggest that the stress generated by tightening of the U-band and the environmental agents affected void generation. Furthermore, stress analysis simulation of the U-band contact region show the presence of tensile stress at regions in contact with the U-band and compressive stress at regions not in contact. The difference in these stresses and the regularity of the molecular arrangement during manufacturing of the pipe likely influences the direction of void generation, which can progress into cracks.

Contamination from plastic pipes in small systems: migration and leaching

In recent years, extensive laboratory-scale research has focused on the biofilm formation, leaching, and migration of organic chemical compounds from plastic pipes into drinking water. This research has been conducted on an existing distribution network in three rural villages near the dead ends to study the small diameter pipes associated with stagnant or low flow conditions. The distribution network was constructed more than ten years ago using unplasticized polyvinyl chloride pipes. Samples of water, soil, and aged pipes have been collected and tested in the laboratory. Results showed a heavy biofilm formed on the inner surfaces of the uPVC pipes. The biofilm has resulted in high concentrations of trihalomethanes, total organic carbon, and PAHs in the drinking water. The predominant PAHs were the acenaphthylene followed by the naphthalene, while no PAHs have detected at the source. The SEM images showed deterioration of pipe walls, swelled parts, and pores. The EDX confirms the migration of some elements including O, Cl, Ca, Ti, Mg, Fe and K due to the biodegradation of the pipe material and the Ca/Zn stabilizers. However, PAHs released from the plastic pipes into the flowing water are caused by metabolic activities. In addition, results showed that the surrounding soil has classified as having low organic content. Hence, uPVC pipes need protection or change in the manufacturing processes to reduce their hazards in distribution networks over time.

Study of Concrete Filled Unplasticized Poly-Vinyl Chloride Tubes as Columns under Axial Loading

This article aims to examine the behavior of Unplasticized Poly- Vinyl-Chloride (UPVC) bounded reinforced columns with polypropylene fibers under axial compression. To develop this model, a no samples of concrete filled UPVC pipe (CFUT) with different geometric properties were tested. To obtain the specimens different class pipes with three different diameters were used to investigate the sensitivity of these columns to various parameters. The effect of each variable on the ultimate strength, ductility and confinement efficiency of the samples was investigated. All specimens were compressed by applying load only to the concrete core to obtain the load-displacement variations and the corresponding deformation mode. A finite element model was developed using the proposed stress-strain variation of confined concrete with UPVC tubes to simulate axial compression of CFUT specimens. According to the results obtained, the effect of the change in diameter-thickness ratio failure stress of concrete limited by (D/t) is obtained and discussed with empirical relationship. Polypropylene fibers were found to slightly increase column strength up to a certain volume fraction, after which the strength generally experienced a decrease.

Fundamental Investigation of Various Factors Affecting the Occurrence of Solvent Cracking for Unplasticized Poly Vinyl Chloride Pipes in Building Equipment

Fundamental Investigation of Various Factors Affecting the Occurrence of Solvent Cracking for Unplasticized Poly Vinyl Chloride Pipes in Building Equipment

Elucidation of the Mechanism of Blockage in Sewer Pipes by Fatty Acid Deposition and Suspended Solid

The objective of this study is to elucidate the mechanism by which blockages occur in sewer pipes following the deposition of fat, oil, and grease (FOG) and suspended solids (SS). In this study, a simulated wastewater flow experiment was conducted to elucidate the mechanism of sewer pipe blockage using lauric acid as fatty acid and florisil to simulate FOG and SS blockages, respectively. Unplasticized polyvinyl chloride pipes (ϕ = 50 mm) with a flow speed of 2 L/min and 1% inclination were used in this experiment. In “Case L & F (lauric acid florisil),” the deposition of florisil and adhesion of solids increased at the bottom of the sewer pipe over a set period. After seven days, decreases in lauric acid concentration from 1000 to 57 mg/L and in Ca2+ concentration from 18 to 0.8 mg/L were observed. FOG deposits formed solids by the saponification of lauric acid and Ca2+ from tap water. In the simulated kitchen wastewater, either lauric acid or florisil exhibited solid deposition and adhesion. Based on these findings, the blockage mechanism was elucidated to confirm FOG deposition of and SS influenced by the combination of lauric acid, Ca2+, and florisil.

Confinement of Recycled Aggregate Concrete (M-20) Using U-PVC Pipe

There is a issue of rusting and brittle failure in building structures so there is a need of more durable structure for better performance. The durability of the structure is affected by the choice of the construction material only .But here our main focus is not only to increase the durability but we are also aiming towards increasing the strength of the structure which can be achieved by the confinement of the column. Studies shows that by confining the column, its strength can be increased significantly. From durability point of view, we have carried out the complete replacement of the natural coarse aggregate with the recycled aggregate in order to know its properties and suitability as a replacement material and to promote the idea of sustainable development. In the present paper, an experimental study is presented regarding the load carrying capacity of the unplasticized poly vinyl chloride (U-PVC) confined columns subjected to axial compressive load. The cylinders that are used for this study are M20 grade concrete cylinders which are made using the recycled coarse aggregates. The cylinders are confined using the U-PVC pipes of 2.5mm & 3.5mm thickness and epoxy resin was used to increase the bond strength between the concrete cylinders & the U-PVC pipes. The cylinders that are used in this study are of length 300mm & diameter 150mm. The concrete used in study are designed as per the latest versions of Indian Standard Code of Practice and are prepared after running various trial mixes. A total of 9 specimens were casted for this study out of which 6 specimens were confined using U-PVC pipes while the other 3 specimens were unconfined. The specimens were subjected to gradual compressive load in universal testing machine (UTM) upto the failure and the results were recorded. The results indicated significant increase in the load carrying capacity of the confined columns as compared to the unconfined columns.

Influence of Backfill Soil Saturation on the Structural Response of Buried Pipes

The structural design of new buried pipes and the calculation of the remaining service life of in-service buried pipes are usually conducted assuming that the backfill soil is at the optimum moisture content using the unsaturated soil parameters published by Boscardin et al. (1990). These unsaturated soil parameters are also implemented in the CANDE software, which is a standard software developed for designing buried culverts/pipes. However, intense rainfall seasons, floods, or water table rise due to changes in local drainage conditions may change the state of the backfill soil from unsaturated to saturated conditions. The purpose of this paper is to study the robustness of using the unsaturated soil parameters in the design of new buried pipes and the calculation of the remaining strength of in-service buried pipes by comparing the response of buried pipes for unsaturated and saturated backfill conditions using three-dimensional finite element analysis. Cast iron, concrete, and unplasticized polyvinyl chloride pipes have been considered to address the aim of the study. The results have shown that the soil saturation increases the stresses of the pipe wall, displacement of the pipe, and the soil pressure applied on the pipe. Hence, there is a need to understand and consider the unsaturated/saturated soil mechanics in the design and the analysis of buried pipes/culverts.

Response of buried uPVC pipes subjected to earthquake shake

The earthquake shake has a significant impact on the response of buried infrastructures; however, no study has been conducted on the behavior of buried flexible pipes subjected to earthquake shake. This paper investigates the transverse response of buried unplasticized polyvinyl chloride pipes subjected to transverse earthquake shake. A robust finite element model has been used to conduct this research. The influence of the pipes’ diameter, backfill height, peak ground acceleration, weight of the backfill, location of the rock layer, and predominant frequency of the earthquake has been investigated to provide insight into the seismic response of these buried flexible pipes. The results showed that the earthquake shake significantly increases the pipe wall thrust, pipe wall bending moment, and vertical diameter change. The results also showed that increasing the backfill height or the peak ground acceleration remarkably increases the earthquake response of the buried pipe. In addition, it was found that the weight of the backfill soil does not have a significant impact on the earthquake response of the pipe. However, the location of the earthquake shake is found to have a notable impact on the seismic response of the pipe; the closer the rock layer to the soil surface, the higher the seismic response. Finally, the results showed that increasing the predominant frequency of the earthquake shake decreases the earthquake response of the pipe. The results reported in this research are very useful to manufacturers of plastic pipes, pipeline design engineers, and researchers interested in the response of buried infrastructures.

Assessment of Axial Capacity of RC Stub Column Confined with Unplasticized Polyvinyl Chloride Pipe

In recent years, strengthening and enhancement of durability of concrete columns have increased significantly in the medium-rise or high-rise buildings across the globe. Strengthening of a concrete column may lead to the section composite as it uses encasing techniques. In this presentation, instead of post-strengthening of columns, the authors wish to utilize the advantage of composite sectional properties to enhance the durability of the concrete column. In general, steel tubes are extensively used for such purpose in the past decades, as design guidelines are available in the literature and various codes of practice. In the present investigation, reinforced concrete-filled unplasticized polyvinyl chloride pipes are taken up as composite column sections to study its structural behavior, viz. failure pattern, bond strength, confinement, and flexural behavior as it simultaneously improves the response with better confinement along with protecting the same from adverse environmental hazards, as well as to study its effectiveness as low-cost housing. Seventy-two confined (filled) column and 27 unconfined column specimens were tested to investigate the effects of various parameters on the ultimate load-carrying capacity and the load–deformation behavior of the columns. All the specimens are found with localized failure. Concrete column exhibits sudden failure when displacement reached the range of 3.4–6.7 mm. While for the confined reinforced concrete column, it reaches 22.3 mm without sudden failure while retaining its integrity. Detail study shows that ductility of specimens increases with the increase in pipe thickness. Finally utilizing the extensive experimental data and with the help of EUROCODE-4, a mathematical model based on response surface methodology has been proposed for the purpose of predicting the load-carrying capacity of the confined as well as unconfined RC stub columns.

Test of polyvinylchloride pipes obtained by optimal extrusion degree orientation method

The object of research in the article is unplasticized polyvinylchloride (UPVC) pipe with outer diameter of 90 mm and a wall thickness of 3,5 mm. Oriented PVC (PVC-O) pipes were made of this pipe. Parameters of these pipes: 110*2 , 9 mm; 125*2 , 5 mm; 140*2 mm. For this purpose it was determined with which optimal extrusion degree PVC-O pipe would have better properties and would be less expensive to manufacture than conventional UPVC pipe. To investigate the optimum extrusion degree it was chosen the acoustic emission research method because it provided the best necessary analytical data. The result to determine the optimal extrusion degree of PVC-O pipes were obtained during the studies and showed the right choice of research method was shown, namely: an optimal variant for obtaining PVC-O pipe from UPVC pipe 90*3,5 mm is the pipe with extrusion degree 1,4, namely 125*2,5, because it can simultaneously reduce wall thickness by 40% and have more time resource of exploitation to the destruction of 77 % compared to the dimension-type pipes 110*2,9 and 140*2,0, one of which has a rougher wall, which increases the cost of the pipe and the other has less time resource of exploitation to the destruction.

Structural response of composite concrete filled plastic tubes in compression

Kenya has recently experienced worrying collapse of buildings during construction largely attributable to the poor quality of in-situ concrete and poor workmanship. The situation in the country is further compounded by rapid deterioration of infrastructure, hence necessitating the development of alternative structural systems such as concrete filled unplasticized poly vinyl chloride (UPVC) tubes as columns. The work herein adds on to the very limited and scanty work on use of UPVC tubes in construction. This study presents the findings of experimental and analytical work which investigated the structural response of composite concrete filled UPVC tubes under compressive load regime. UPVC pipes are cheaper than steel tubes and can be used as formwork during construction and thereafter as an integral part of column. Key variables in this study included the strength of infill concrete, the length to diameter ratio (L/D) of the plastic tube, as well as the diameter to thickness ratio (D/2t) of the plastic tube. Plastic tubes having varying diameters and heights were used to confine concrete of different strengths. Results obtained in the study clearly demonstrate the effectiveness of UPVC tubes as a confining medium for infill concrete, attributable to enhanced composite interaction between the UPVC tube and infill concrete medium. It was determined that compressive strength of the composite column specimens increased with increased concrete strength while the same decreased with increased column height, albeit by a small margin since all the columns considered were short columns. Most importantly, the experimental confined concrete strength increased significantly when compared to unconfined concrete strength; the strength increased between 1.18 to 3.65 times the unconfined strength. It was noted that lower strength infill concrete had the highest confined strength possibly due to enhanced composite interaction with the confining UPVC tube. The study further proposes an analytical model for the determination of confined strength of concrete.

Finite Element Analysis of Buried UPVC Pipe

Background/Objectives: Understanding the mechanics of buried pipes is complicated due to the imprecision in the properties of the soil envelope. This paper deals with the study of behavior of flexible Un-Plasticized Poly Vinyl Chloride pipes buried in loose and dense sand backfill. Methods/Statistical Analysis: A design methodology is proposed for prediction of the performance of pipes using the finite element method ANSYS. The pipe soil interaction under static loading conditions is investigated. Height of the soil above the pipe varies with the ratios of diameter of the pipe. The numerical results are compared with the available values calculated using the theoretical approach Spangler Deflection theory. Findings: Provision of geogrid reinforcement above the crown of buried pipe is suggested to minimize the vertical deflection of buried Un-Plasticized Poly Vinyl Chloride pipes.

Investigation of Organic Compounds Migration from Polymeric Pipes into Drinking Water under Long Retention Times

Unplasticized polyvinyl chloride pipes (uPVC), Polypropylene random pipes (PPR) and Polyethylene pipes (PE) for drinking water were tested with respect to migration of total organic carbon (TOC) into water. The investigation was carried out under different long retention times aiming to investigate TOC migration trends of different polymeric pipes over time and the corresponding water quality changes like chlorine decay. Experiment results showed TOC release from all pipes increased significantly over time. PE pipe showed the highest TOC concentrations among all tested pipe materials in this study. Chlorine consumption data observed in this research followed the shape of TOC values.

The work of fracture in uniaxial and biaxial oriented unplasticised polyvinylchloride pipes

In oriented unplasticised polyvinylchloride (uPVC) pipes, cracks propagate tangentially rather than through the wall as in conventional pipe. Notched impact, a modified peel test and the specific work of fracture approach have been used to measure fracture toughness of a conventionally extruded, a uniaxially oriented and a biaxially oriented uPVC pipe in different directions. The different failure mode for the oriented pipes was found to result from an order of magnitude increase in the fracture toughness for cracks propagating perpendicular to the orientation direction. Differences in the fracture toughness between the oriented pipes were also related to their molecular orientation.

Migration of lead from unplasticized polyvinyl chloride pipes

The effect of water quality parameters, such as water pH, temperature, and total dissolved solids (TDS), and direct exposure to UV-radiation on the migration of lead, tin and other metal stabilizers, such as calcium, cadmium, and barium from unplasticized polyvinyl chloride (uPVC) pipes were investigated using locally manufactured pipes. Specimens of 1 m were used to investigate the effect of water quality parameters using the circulatory method. To investigate the effect of UV-radiation, specimens of 33 cm long were used throughout the research. The investigation was carried out, using the static method at different times of exposure to the UV-radiation. The concentrations of lead, tin, and other metal stabilizers in the water were evaluated using the inductively coupled argon plasma (ICAP) technique. The results on the effect of water quality parameters showed that water pH, temperature, TDS, and time of water circulation were all having an effect on the migration of lead, tin, and other metal stabilizers. On the other hand, exposure to UV-radiation was seen to promote the migration of lead, tin, and other metal stabilizers. A lead concentration of about 0.8 mg/l (ppm) was detected after 14 days of exposure to the UV-radiation.

Optical measurement of smoke

AbstractThe optical density of smoke liberated by burning seven samples of materials and six commercial plastic products was studied using different light sources in a modified NBS smoke chamber. Materials included plywood, PMMA (polymethylmethacrylate), PF (phenolformaldehyde), PE (polythene), PC (polycarbonate), PP (polypropene) and POM (acetal). The plastic products were a polyvinylchloride pipe, an unplasticized polyvinylchloride pipe, a telephone casing, an insulator, an electrical fitting and floor tiles. Light sources used were a helium‐neon laser, a mercury lamp, a sodium lamp and a tungsten filament lamp. The errors in optical measurement of smoke due to a forward‐scattering effect and the frequency of light beam were investigated.

Combustion characteristics of UPVC pipe grade materials

AbstractSamples of current Australian production of unplasticized polyvinyl chloride pipe and fitting materials have been examined in relation to combustion characteristics. Small scale laboratory assessment of piloted radiant ignition flame propagation and smoke generation have been investigated. Where necessary, improvements to methods of test or analysis of data have been developed and factors that influence results have been investigated. Piloted radiant ignititon and smoke production under flaming conditions are shfown to be the important combustion characteristics of UPVC materials for improvement.