scholarly journals Hydrothermal Ageing Effect on Reinforcement Efficiency of Nanofibrillated Cellulose/Biobased Poly(butylene succinate) Composites

Polymers ◽  
2022 ◽  
Vol 14 (2) ◽  
pp. 221
Author(s):  
Olesja Starkova ◽  
Oskars Platnieks ◽  
Alisa Sabalina ◽  
Sergejs Gaidukovs

Nanofibrillated cellulose (NFC) is a sustainable functional nanomaterial known for its high strength, stiffness, and biocompatibility. It has become a key building block for the next-generation of lightweight, advanced materials for applications such as consumer products, biomedical, energy storage, coatings, construction, and automotive. Tunable and predictable durability under environmental impact is required for high performance applications. Bio-based poly (butylene succinate) (PBS) composites containing up to 50% NFC content were designed and aged in distilled water or at high relative humidity (RH98%). PBS/NFC composites are characterized by up to 10-fold increased water absorption capacity and diffusivity and the data are correlated with model calculations. Aged samples exhibited decreased crystallinity and melting temperature. Incorporation of NFC into PBS showed up to a 2.6-fold enhancement of the elastic modulus, although accompanied by a loss of strength by 40% and 8-fold reduction in the strain at failure of maximally loaded composites. Hydrothermal ageing had almost no influence on the tensile characteristics of PBS; however, there were considerable degradation effects in PBS/NFC composites. Altered reinforcement efficiency is manifested through a 3.7-fold decreased effective elastic moduli of NFC determined by applying the Halpin–Tsai model and a proportional reduction of the storage moduli of composites. The adhesion efficiency in composites was reduced by hydrothermal ageing, as measured Puckanszky’s adhesion parameter for the strength, which decreased from 3 to 0.8. For the loss factor, Kubat’s adhesion parameter was increased by an order. PBS filled with 20 wt.% NFC is identified as the most efficient composition, for which negative environmental degradation effects are counterbalanced with the positive reinforcement effect. The PBS matrix can be used to protect the NFC network from water.

2021 ◽  
Vol 4 (1) ◽  
pp. 46-56
Author(s):  
Çağlar Yalçınkaya

Ultra-high-performance concrete (UHPC) is an innovative cementitious composite containing steel fiber reinforcement that can improve the behavior of structural elements thanks to its high strength and improved ductility properties. The mix design that provides these superior properties of UHPC also makes it a high-cost material. For this reason, the use of UHPC in parts where it contributes more significantly to the performance of the structural elements will lower down the costs and reduce the negative environmental effects caused by high cement content. In this preliminary study, the production of normal concrete (NC)-UHPC reinforced concrete (RC) composite beams by wet-on-wet casting was investigated by producing mini-RC beams. In the production of mini-RC beams, normal mortar (NM) and self-compacting mortar (SCM) mixtures were used to represent an NC. The results showed that in the production of NC-UHPC composite beams, the mixtures should have different rheological properties depending on the order of the layers. Increasing the total thickness of the UHPC layer enhanced the initial and yield stiffnesses as well as the peak loads. UHPC layer with thicknesses of 15 mm in tension zone, 30 mm in tension zone, and 15+15 mm in tension+compression zone led to the load-carrying capacity increment ratios of 20%, 34.6%, and 24.3%, respectively. However, increasing the thickness of the UHPC layer in the composite beams, especially more than 15 mm, reduced the ductility ratio and energy absorption capacity. Optimizing the tensile reinforcement ratio in UHPC layers can overcome the drawbacks in the ductility.


2021 ◽  
Vol 6 (1) ◽  
pp. 2
Author(s):  
Olesja Starkova ◽  
Oskars Platnieks ◽  
Alisa Sabalina ◽  
Sergejs Gaidukovs

Biobased polymers and composites have gained increased global attention due to their abundance, renewability, and biodegradability. Natural fillers such as cellulose-based fillers improve the mechanical properties of biopolymers, extending their application range, while maintaining the eco-friendly characteristics of the materials. Mowing towards engineering applications, requirements imposed on materials’ durability with regard to their environmental impact and high performance is necessary. Variations of ambient humidity and temperature could essentially reduce the service lifetime of biobased polymer composites. This study is focused on the hydrothermal degradation of poly(butylene succinate) (PBS) filled with nanofibrillated cellulose (NFC) by up to 50 wt.% aimed at identifying the most efficient PBS/NFC composition, while maintaining a reasonable balance between the reinforcement effect and accelerated degradation that is inherent for most natural fillers. Water absorption and its effect on the structure, thermal, mechanical, and thermomechanical properties were studied. High reinforcement and adhesion efficiency is obtained for PBS/NFC composites and their properties are reasonably retained after hydrothermal ageing. Their water absorption capacity and diffusivity increased significantly with the NFC content in PBS. The degradation of the mechanical properties occurs to a greater extent with an increased NFC content in the polymer matrix. PBS, filled with 20 wt.% of NFC, is identified as the most efficient composition, for which the negative environmental degradation effects are counterbalanced by the positive reinforcement effect.


2019 ◽  
Vol 8 (3) ◽  
pp. 5990-5994 ◽  

In the present study, high strength high volume fly ash concrete of M70 grade is developed and its durability properties such as water absorption capacity, porosity, and sorptivityare ascertained. It was found that high volume fly ash does not yield high strength so silica fume is added for early strength gain and for later strength gain lime required for complete pozzolonic action is added to achieve high performance concrete. In this study after testing for various combinations of quaternary blended concrete it was reported that 30% cement +70% fly ash as total powder achieves high strength of nearly 70 MPa, when silica fume of 10% by weight of powder and 30% of lime by weight of powder are added to the total powder content. The high strength high volume concrete developed with this optimum quantities of quaternary blends will be evaluated for the performance.It was found that water absorbtion in high strength high volume fly ash concrete reduced by nearly 85% and porosity is reduced by 34%.


Alloy Digest ◽  
1973 ◽  
Vol 22 (9) ◽  

Abstract BERYLCO 25 is the standard high-performance beryllium copper alloy most widely used because of its high strength, hardness and excellent spring characteristics. BERYLCO 25 is the updated version of BERYLCO 25S (Alloy Digest Cu-3, November 1952). This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Cu-271. Producer or source: Kawecki Berylco Industries Inc..


Alloy Digest ◽  
1995 ◽  
Vol 44 (7) ◽  

Abstract ALUMINUM ALLOY 201.0 is a structural casting alloy available as sand, permanent mold and investment castings. It is used in structural casting members, applications requiring high tensile and yield strengths with moderate elongation, and where high strength and energy-absorption capacity are needed. This datasheet provides information on composition, physical properties, and elasticity as well as creep and fatigue. It also includes information on high temperature performance as well as casting, heat treating, machining, joining, and surface treatment. Filing Code: AL-336. Producer or source: Various aluminum companies.


Alloy Digest ◽  
1990 ◽  
Vol 39 (2) ◽  

Abstract ARMCO PH 13-8Mo is designed for high-performance applications requiring high strength coupled with excellent resistance to corrosion and stress corrosion. It has excellent toughness, good transverse properties and excellent forgeability. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness. It also includes information on low and high temperature performance, and corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: SS-224. Producer or source: Baltimore Specialty Steels Corporation. Originally published May 1969, revised February 1990.


Alloy Digest ◽  
2019 ◽  
Vol 68 (2) ◽  

Abstract Strenx 100 is a high-strength, high-performance structural steel with a minimum yield strength of 690 MPa (100 ksi). It meets the requirements of ASTM A514 Grade S. Strenx 100 is a US Customary steel similar to Strenx 700 (Alloy Digest SA-779, February 2017). This datasheet provides information on composition, physical properties, and tensile properties. Filing Code: SA-838. Producer or source: SSAB Swedish Steel Inc..


Alloy Digest ◽  
2016 ◽  
Vol 65 (2) ◽  

Abstract Outokumpu Type 630 is a martensitic age hardenable alloy of composition 17Cr-4Ni. The alloy has high strength and corrosion resistance similar to that of Type 304 stainless steel. This datasheet provides information on composition, physical properties, hardness, and tensile properties as well as fracture toughness. It also includes information on corrosion resistance as well as forming, heat treating, and joining. Filing Code: SS-1238. Producer or source: Outokumpu High Performance Stainless.


1999 ◽  
Vol 5 (1) ◽  
pp. 29-40
Author(s):  
R. Krumbach ◽  
U. Schmelter ◽  
K. Seyfarth

Abstract Variable obsen>ations concerning frost resistance of high performance concrete have been made. The question arises which are the decisive factors influencing durability under the action of frost and de-icing salt. The proposed experiments are to be carried out in cooperation with F.A.- Finger - Institute of Bauhaus University Weimar. The aim of this study is to determine possible change of durability of high strength concrete, and to investigate the origin thereof. Measures to reduce the risk of reduced durability have to be found.


Author(s):  
C. Sauer ◽  
F. Bagusat ◽  
M.-L. Ruiz-Ripoll ◽  
C. Roller ◽  
M. Sauer ◽  
...  

AbstractThis work aims at the characterization of a modern concrete material. For this purpose, we perform two experimental series of inverse planar plate impact (PPI) tests with the ultra-high performance concrete B4Q, using two different witness plate materials. Hugoniot data in the range of particle velocities from 180 to 840 m/s and stresses from 1.1 to 7.5 GPa is derived from both series. Within the experimental accuracy, they can be seen as one consistent data set. Moreover, we conduct corresponding numerical simulations and find a reasonably good agreement between simulated and experimentally obtained curves. From the simulated curves, we derive numerical Hugoniot results that serve as a homogenized, mean shock response of B4Q and add further consistency to the data set. Additionally, the comparison of simulated and experimentally determined results allows us to identify experimental outliers. Furthermore, we perform a parameter study which shows that a significant influence of the applied pressure dependent strength model on the derived equation of state (EOS) parameters is unlikely. In order to compare the current results to our own partially reevaluated previous work and selected recent results from literature, we use simulations to numerically extrapolate the Hugoniot results. Considering their inhomogeneous nature, a consistent picture emerges for the shock response of the discussed concrete and high-strength mortar materials. Hugoniot results from this and earlier work are presented for further comparisons. In addition, a full parameter set for B4Q, including validated EOS parameters, is provided for the application in simulations of impact and blast scenarios.


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