scholarly journals Short- and Long-Term Structural Characterization of Cured-in-Place Pipe Liner with Reinforced Glass Fiber Material

Author(s):  
Hyon Wook Ji ◽  
Dan Daehyun Koo ◽  
Jeong-Hee Kang

Cured-in-place pipe (CIPP), as a kind of trenchless sewer rehabilitation technology, is a method to repair sewer pipe using unsaturated polyester resin. This study develops a CIPP liner using hot water or steam curing as well as glass fiber, in contrast to traditional methods, which use nonwoven fabric. Composite material samples were fabricated by combining liner materials using various methods, and the structural characteristics of the liners were compared and analyzed through short- and long-term flexural strength tests. A long-term test was conducted for 10,000 h, and the results revealed 13.3 times higher flexural strength and 8 times higher flexural modulus than the American Society for Testing Materials minimum criteria for CIPP short-term properties. The maximum creep retention factor was 0.64, thereby reducing the design thickness of the CIPP by up to 54%. The structural characteristics also improved when glass fibers were mixed with traditional CIPP liner, making it possible to reduce the thickness by 30%. Glass fibers result in high structural strength when combined with unsaturated polyester resin. Structural strength increased, even when glass fibers were mixed with traditional CIPP liner. The main contribution of this research is the development of a high strength CIPP liner and improvement of the structural properties of CIPP lining without using the specially formulated resin or lining materials.

2019 ◽  
Vol 24 ◽  
pp. 1-7
Author(s):  
Md. Naimul Islam ◽  
Harun Ar-Rashid ◽  
Farhana Islam ◽  
Nanda Karmaker ◽  
Farjana A. Koly ◽  
...  

E-glass fiber mat reinforced Unsaturated Polyester Resin (UPR)-based composites were fabricated by conventional hand lay-up technique. The fiber content was varied from 5 to 50% by weight. Mechanical properties (tensile and bending) of the fabricated composites were investigated. The tensile strength (TS) of the 5% and 50% fiber reinforced composites was 32 MPa and 72 MPa, respectively. Similarly, tensile modulus, bending strength and bending modulus of the composites were increased by the increase of fiber loading. Interfacial properties of the composites were investigated by scanning electron microscopy (SEM) and the results revealed that the interfacial bond between fiber and matrix was excellent. Keywords: Unsaturated Polyester Resin, Mechanical Properties, E-glass Fibers, Composites, Polymer.


Polymers ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2211
Author(s):  
S.M. Sapuan ◽  
H.S. Aulia ◽  
R.A. Ilyas ◽  
A. Atiqah ◽  
T.T. Dele-Afolabi ◽  
...  

This work represents a study to investigate the mechanical properties of longitudinal basalt/woven-glass-fiber-reinforced unsaturated polyester-resin hybrid composites. The hybridization of basalt and glass fiber enhanced the mechanical properties of hybrid composites. The unsaturated polyester resin (UP), basalt (B) and glass fibers (GF) were fabricated using the hand lay-up method in six formulations (UP, GF, B7.5/G22.5, B15/G15, B22.5/G7.5 and B) to produce the composites, respectively. This study showed that the addition of basalt to glass-fiber-reinforced unsaturated polyester resin increased its density, tensile and flexural properties. The tensile strength of the B22.5/G7.5 hybrid composites increased by 213.92 MPa compared to neat UP, which was 8.14 MPa. Scanning electron microscopy analysis was used to observe the fracture mode and fiber pullout of the hybrid composites.


Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7307
Author(s):  
Xinjun Fu ◽  
Xiaojun Wang ◽  
Jinjian Zhu ◽  
Minzhuang Chen

Long chopped glass fiber reinforced low-density unsaturated polyester resin (LCGFR-LDUPR) composite materials with light weight and excellent mechanical properties were prepared. It was proved that long chopped glass fiber, which was in length of 15.0 mm and chopped from ER4800-T718 plied yarn, was suitable for the preparation of LCGFR-LDUPR composite samples. With the coexistence of 1.50 parts per hundred of resin (phr) of methyl ethyl ketone peroxide (MEKP-II) and 0.05 phr of cobalt naphthenate, optimal preparation parameters were obtained, which were 20.00 phr of long chopped glass fiber, 2.50 phr of NH4HCO3, at a curing temperature of 58.0 °C. The lowest dosage of activated radicals produced by MEKP-II and cobalt naphthenate enabled the lower curing exothermic enthalpy and the slowest crosslinking for unsaturated polyester resin to carry out, resulting in a higher curing degree of resin. It was conducive to the formation, diffusion, and distribution of bubbles in uniform size, and also for the constitution of ideal three-dimensional framework of long glass fibers in the cured sample, which resulted in the LCGFR-LDUPR composite sample presenting the apparent density (ρ) of 0.68 ± 0.02 g/cm3, the compression strength (P) of 35.36 ± 0.38 MPa, and the highest specific compressive strength (Ps) of 52.00 ± 0.74 MPa/g·cm3. The work carried out an ideal three-dimensional framework of long chopped glass fiber in the reinforcement to low-density unsaturated polyester resin composite samples. It also presented the proper initiator/accelerator system of the lower curing exothermic enthalpy and the slowest crosslinking for unsaturated polyester resin.


Author(s):  
L. H. Hsu ◽  
C. T. Lu ◽  
G. F. Huang ◽  
J. T. Chen ◽  
W. C. Chuang ◽  
...  

This article introduced a type of rapid prototyping (RP) transtibial socket that is fabricated by a fused deposition modeling (FDM) machine and wrapped with a layer of unsaturated polyester resin (UPR) to enhance its flexural strength. As current rapid prototyping machines use a layer-based process to manufacture products, this will result in RP products liable to break along forming layers once bending moment is applied. To prevent RP prosthetic socket from breakage, this study proposed wrapping a layer of unsaturated polyester resin around a preliminary thin RP socket to reinforce its flexural strength. Factors affecting the strength of the resin-reinforced RP socket include thickness and forming orientation of the preliminary RP socket, thickness of the UPR layer, and type of material used to make the preliminary RP socket. Employing Taguchi experimental design method and ASTM three-point bending test standard, the parameters that influence the flexural strength of the resin-reinforced RP prosthetic socket can be determined. Based on the appropriate parameters, including thickness of the RP layer and UPR layer, the RP material and RP fabricating orientation, the preliminary thin RP prosthetic sockets can be fabricated by an FDM machine. And the thin layer preliminary RP sockets were then wrapped with cotton socks and laminated UPR layer to form resin-reinforced RP sockets. To confirm the effectiveness of the resin-reinforced sockets developed in this study, the pressures at residual limb/socket interface were measured by using a pressure distribution measurement system and movement was captured by a motion analysis system while a patient wears the resin-reinforced RP socket. Two resin-reinforced RP sockets have been fabricated and tested by a volunteer amputee. Analysis of the experimental results would assist a prosthetist to assess the distribution of interface pressures at the pressure-tolerant (PT) and pressure-relief (PR) areas of the residual limb. And, the gait pattern will be used to evaluate the applicability while the resin-reinforced RP socket is worn. Trial uses for durability test of the proposed RP socket are being arranged.


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