bluuebunny/crossref_metadata_2025 huggingface dataset:
Green Synthesis of 10 nm Gold Nanoparticles via Seeded-Growth Method and its Conjugation Properties on Lateral Flow Immunoassay
Authors: Siti Rabizah Makhsin , Khairunisak Abdul Razak , Azlan Abdul Aziz , Noordin Rahmah
Published: April 2013

In this work, 10 nm gold nanoparticles (AuNPs) was successfully synthesized via seeded-growth method. The green chemically synthesis of this AuNPs becomes attractive because the growth process does not involve heat. Moreover, this technique has advantages of quick, simple, and low cost process. Sodium borohydrate (NaBH4) was used as a reducing agent while trisodium citrate was used as a source of OH- ions in the seed stage. Hydroxylamine hydrochloride (NH4.3H2O) was used as a slow reducing agent to enlarge 4 nm seeds to 10 nm AuNPs. A 4 ml AuNPs seed was the optimized volume to produce 10 nm AuNPs with great homogeneity and dispersity. A sharp peak of surface plasmon resonance (SPR) measurement at 517 nm proved that 10 nm AuNPs was successfully synthesized via this method. Optical properties of the seeds and grown AuNPs were analyzed using UV-Vis spectroscopy while size and surface morphology were observed using a transmission electron microscopy (TEM). Particle size distribution was measured using Zetasizer. 10 nm AuNPs was then conjugated with streptavidin and goat anti-human IgA. Depending on type of protein, 10 µg/ml of streptavidin and 11.2 µg/ml of goat anti-human IgA were required to conjugate with 10 nm AuNPs. The produced products had binding capability on lateral flow immunoassay (LFI). A few nanometer red-shifted absorption spectrum of 10 nm AuNPs conjugated protein revealed successful conjugation instead of agglomeration. 1% BSA was determined as the optimum concentration to stabilize 10 nm AuNPs conjugated biomolecules.
Activated Carbon Fiber Derived from Pyrolysis of Palm Fiber
Authors: Lee Ting , Matsumoto Akihiko , Othman Radzali , Yeoh Fei Yee
Published: April 2013

Palm empty fruit bunch (EFB) is an abundant by-product resulted from massive palm oil production in Malaysia as one of the world's largest exporter and second largest producer of palm oil. This agricultural waste is usually disposed in nature, burnt in opened atmospheres, or used as a fuel for boilers. Such conventional handlings of EFB have created environmental concerns to Malaysia such as air pollution and release of green house gases (CH4 and CO2). This study made use of such biomass in the production of cost effective nanoporous material, namely activated carbon fiber (ACF) which able to diminish the problem of waste disposal, and at the same time to turn waste into wealth. This is especially beneficial when the ACF is used for environmental friendly application such as adsorbed natural gas (ANG) technology. ACF was formed from carbonaceous materials via process of carbonisation and activation. Both chemical and physical activations were carried out by using H2SO4 and CO2, respectively. In pyrolysis, carbonisation was conducted at temperatures i.e. 400, 600, 800 and 1000 °C in nitrogen (N2) atmosphere. Surface morphologies, microstructures, pore structures and surface chemistry of these samples were investigated for the characterisation of EFB fiber-derived ACF. Above 80% of the total pore volumes for the samples were contributed by the micropore as the major pore components in the ACF produced. The samples exhibited an high BET surface area , dominant micropore volume up and narrow pore size distribution in micro range (< 1.5 nm).
Impact of Silane and Siloxane Based Hydrophobic Powder on Cement-Based Mortar
Authors: Spaeth Valerie , Lecomte Jean Paul , Delplancke Marie Paule , Orlowsky Jeanette , Büttner Till
Published: April 2013

Impact of the addition of silane and siloxane based hydrophobic powders on cement based mortar was studied. Effect of powder addition on mechanical properties and water absorption of cement based mortar is described. Impact of accelerated ageing, including UV radiation, and rain-sun cycles on hydrophobic performance was assessed, demonstrating excellent durability of silane-based hydrophobic performance.
Experimental Investigation on Mix Design and Mechanical Properties of Polymer (Latex) Modified Concrete
Authors: Nabavi Farhad , Nejadi Shami , Samali Bijan
Published: April 2013

This paper presents the experimental investigation to enhance the mechanical properties of Polymer Modified Concrete (PMC) incorporating Styrene Butadiene Rubber (SBR) and describes the potential of using PMC as a structural material. PMC has been used for many years as an over layer in the bridges deck or for the repairing the defected concrete structures subjected to marine environment. But, because of low compressive strength due to foaming phenomenon, PMC has not been considered as a structural concrete. In this study, a range of investigations including sensitivity of PMC to water cement ratio, the effect of SBR proportion on compressive strength and modulus of rupture, selection of the proper antifoaming agent, the effect of various curing methods on compressive strength, proper mix design of PMC to achieve medium to high compressive strength are carried out. Also, the instructions for casting PMC are composed which can be stated as a standard for mixing and curing procedure of PMC. Results show that increasing the proportion of latex in PMC causes the strength reduction. But, using appropriate antifoaming agent (defoamer) and proper curing method, the mechanical properties can be recovered remarkably.
Hard and Soft: Principles of Polyner-Impregnated Concrete Using Elastomers
Authors: Weichold Oliver , Antons Udo
Published: April 2013

The effect of incorporating elastomeric domains in concrete is described from the point of fracture mechanics. Concrete is subject to brittle failure, since cracks propagate at an enormous speed in the crystalline matrix. However, micro cracks are attracted to volume elements with lower elastic moduli such as elastomeric domains. Cracks that encounter the concrete-elastomer interface are stopped since energy is dissipated by plastic deformation of and/or crack deflection by the elastomer. The domain size and the distribution of the elastomer as well as, and properties of the elastomer-concrete interface are crucial parameters. Such a combination differs substantially from previously prepared polymer-impregnated concretes, in which only glassy polymers were used.
Strength Development Characteristics and Economic Efficiency of Low Temperature Cured Acrylic Polymer Concrete: The Effect of Additive Type
Authors: Yeon Kyu Seok , Choi Yoon Sang , Kawakami Makoto , Seung In Bae , Yeon Jung Heum
Published: April 2013

This paper presents the strength development characteristics and the economic efficiency of low temperature cured acrylic polymer concrete containing different types of additives. In this study, two separate cases were mainly investigated: (1) when only MAA (polar monomer) was used as an additive and (2) when silane (coupling agent) in combination with TMPTMA (cross-linking agent) was used as an additive. The experimental results showed that compressive strength of over 80 MPa could be obtained in both cases even in low curing temperatures (i.e., 0 and -20°C). Also, the result of economic efficiency analysis showed that the use of MAA yielded a 10% less material cost than the use of TMPTMA and silane. This finding indicates that the use of MAA can be more beneficial from an economic perspective.
Influence of Acidic Environments on Cement and Polymer-Cement Concretes Degradation
Authors: Sokołowska Joanna Julia , Woyciechowski Piotr , Adamczewski Grzegorz
Published: April 2013

Cement concrete is hardly considered as the acid resistant material however it should be possible to compare the ability of various cement based composites to resist the sever and chemically aggressive environments. The paper presents assessment of the resistance of cement concretes (of two types of mineral binders) as well as polymer-cement concretes (PCC) to hydrochloric acid. Due to the lack of proper standard procedures the tests were conducted according to the DBME own procedure: concrete specimens were exposed to acids of various concentrations and for various exposure times. The criteria for evaluation the concrete ability to resist the chemical attack were changes of mass, compressive and flexural strength. As PCC is considered to be a composite of better chemical tolerance it was treated as a kind of the reference material (chosen PCC characterized with similar compressive strength level as the previously introduced cement concretes). Approach used in the presented research enabled to compare different composites of similar compressive strength, the basic property to be taken into account in the design of the concrete and reinforced concrete structures.
Bond Strength of Polymer Cement Slurry-Coated Rebar Using EVA Latex in Cement Concrete
Authors: Jo Young Kug , Jeong Seon Ho , Kim Wan Ki
Published: April 2013

Polymer cement slurry(PCS) made from organic polymer dispersion and cement has good adhesion to steel, waterproofness and acid resistance due to being of polymer films formed in the cement slurry. The purpose of this study is to evaluate the mix conditions such as coating thicknesses, curing ages and polymer-cement ratios of PCS-coating material effected on improvement in bond strength of rebar coated by PCS with EVA latex in cement concrete. The test pieces are prepared with four types of polymer-cement ratio, four types of coating thickness and four types of curing age, and tested for the bond strength test. From the test results, in general, bond strength of PCS-coated rebar is better than that of uncoated rebar and epoxy-coated rebar. It is also high bond strength at curing ages of 7-day or less, and coating thicknesses of 75 µm and 100 µm. The maximum bond strength of PCS-coated rebar at curing age of 3-hour is almost same as that of curing age of 1-day and 7-day. The maximum bond strength of PCS-coated rebar with EVA at polymer-cement ratio of 50%, and coating thickness of 100 µm is about 1.41 and 1.47 times respectively, the strength of uncoated rebar and epoxy-coated rebar. It is apparent that the curing age, coating thickness and polymer-cement ratio are very important factors to improve the bond strength of PCS-coated rebar to cement concrete. We can have basic information that it can replace epoxy coated rebar by the PCS-coated rebar with curing age at 3-hour and coating thickness of 100 µm.
Properties of Polymer Modified Concrete in Fresh and Hardened State
Authors: Ion Ioana , Barroso Aguiar José , Angelescu Nicolae , Stanciu Darius
Published: April 2013

It was carried out a study on the properties of polymer modified concrete (PCM) in fresh and hardened state. It was used three types of polymers: epoxy resins, polyurethane and methylcellulose in different percentages and different water cement ratio. The main objectives was to improve workability and rheological behavior of these mixtures in fresh state and mechanical strength tests on hard concrete. Has been investigated the polymer influence on compression strength and flexural strength and analyzing the time evolution of these strengths and participation of polymer in the microstructure formation.
Waterproof Performance of Polymer-Modified Cement Mortar
Authors: Wang Ru , Ma Dao Xun , Wang Pei Ming
Published: April 2013

This paper tested the capillary water absorption, impermeability and cracking of cement mortars modified with three polymers respectively and founded the correlation of cracking with the waterproof performance. The results show that with the polymer content increasing, especially as the polymer/cement ratio (mp/mc) increases from 0% to 5%, the reduction in the capillary water absorption and the penetration depth of water into mortar is significant. When the mp/mc is more than 15%, the increase of the mp/mc in all mortars has little effect on the capillary water absorption and the penetration depth. For the purpose of reducing the cracking weighted value, the styrene-butadiene rubber (SBR) dispersion and the styrene-acrylic copolymer (SAE) powder are superior to the SAE dispersion. Regardless what kinds of polymers, the capillary water absorption and the penetration depth of water into mortar show exponential growth with the increasing cracking weighted value.
Rearch on the Water Repellency of Inorganic Insulation Mortar
Authors: Guan Wen , Ye Bei Hong , Zhao Li Qun , Xuan Jin Qi
Published: April 2013

Three kinds of methods to improve the hydrophobicity of inorganic insulation mortar is studied in this paper.The results show that, the three methods have different influences on the water absorption rate of inorganic insulation mortar. Adding silane in mortar effects most and the surface modification of vitrified small ball effects least. Using the surface modification of vitrified small ball and spraying silane on the mortar surface together has little influence on the water repellency of mortar. However using of adding silane in mortar and spraying silane on the mortar surface together has remarkable influence. Using the three methods together will effect most.
Possibilities of Using Waste Diatomaceous Earth for Polymer-Modified Mortar
Authors: Žižková Nikol , Drochytka Rostislav
Published: April 2013

The paper focuses on results obtained in solving the research and development project of lightweight Polymer-Modified Mortars (PMM). With regard to the currently on-going repairs and reconstructions of panel houses in the Czech Republic approaching the end of their expected lifetime, attention is paid to PMM (Polymer-Modified Mortars) intended for surface treatment such as screed or adhesive materials. For the design of adhesive and screeding substances (recommended for ETICS – External Thermal Insulation Composite Systems) use the alternative raw material sources, waste diatomaceous earth is used from the production at the firm LB MINERALS, s.r.o. (Czech Republic). This raw material is delivered in moist, therefore, it is necessary to dry it before the use and consequently mill it so to be able to replace milled limestone by the modified diatomaceous earth in the original formula.
Research on the Fatigue Behavior of Cement Asphalt Mortar Exposed to Water
Authors: Wang Fa Zhou , Yang Jin , Hu Shu Guang , Zhang Yun Hua , Liu Yun Peng
Published: April 2013

Water erosion is one of the major factors for performance degradation of cement asphalt mortar (abbreviated to CA mortar, or CAM). In this paper, the influence of gap depth, coupling effect of water and pressure on the fatigue behavior of CA mortar was investigated. Results indicated that the damage of bonding surface became more seriously with the increase of gap depth, and when the gap depth was 19 to 38% of the structure size, the destruction exacerbated. Results also indicated that CA mortar was damaged more seriously under the coupling effect of water and pressure; the destruction first occurred on the surface between slab track and CA mortar rather than that between concrete roadbed and CA mortar. Timely repair with epoxy resin prevented the further water erosion well, and improved the service life of CA mortar.
Sustainable Concrete; Is Nanotechnology the Future of Concrete Polymer Composites?
Authors: Czarnecki Lech
Published: April 2013

Sustainable development as the leading civilization idea, and nanotechnology as the contemporary wave of technology significantly affecting the society, are brought together in this paper. A brief history of sustainability implementation from the start concept until European Construction Product Regulation is presented. The extended definitions of sustainable construction and sustainable material are analysed with adequate conclusions towards Concrete. The category of Exergy is implemented as a measure for “natural environmentally-friendly” meaning. The generalised concrete development curve is presented with discussion of Well Defined Concrete Performance. The statement that the sustainability is necessity for concrete and the nanotechnology is the chance for the future of concrete polymer composite is the final conclusion of the paper.
Fluid Transport Mechanisms in Portland Cement Mortar Modified with PVA and Nano Montmorillonite
Authors: Piqué Teresa María , Fernandez Luco Luis , Vázquez Analía
Published: April 2013

The development of new materials for specific applications is an increasing field in the construction industry, so is the employment of nanotechnology for this goal. When poly(vinyl alcohol) (PVA) is added to a Portland cement mortar, a film is formed in between the hydration products. This film has low elasticity modulus and high tensile strength and it enhances the mortar’s mechanical properties in the fresh and hardened states. The addition of nano montmorillonites (MMT) gives the polymer a better compatibility with the cement matrix. In this work, the changes in the microstructure of Portland cement mortars modified with PVA and PVA with MMT are assessed by means of transport of fluids capacity as an indicator. The reference is a standard mortar according to EN 196-1. The parameters measured are: weight loss under drying and air permeability. Complementary measures, such as compressive and flexural strengths and drying shrinkage have also been performed. From the obtained results, it can be concluded that the inclusion PVA + MMT to Portland cement mortar doesn’t affect the microstructure, when compared with Portland cement mortar with PVA, and even increase its tensile strength.
Influences of Superplasticizer on the Interaction between Latex Particles and Cement Grains
Authors: Han Dong Dong , Li Jin Mei , Chen Wei Deng , Zhong Shi Yun
Published: April 2013

In order to have a better understand on the interaction among superplasticizer, latex and cement grains in the fresh cement paste, the zeta potential and the adsorption of polymer on the cement were investigated in this study. The zeta potential was measured by using the ZetaProbe instrument, and the adsorption rate of latex was analyzed by sedimentation test. The zeta potential results show that the zeta potential of pure cement paste is positive and increasing slightly along the first 30mins; the latex particles can be adsorbed by cement grains, comparing with SAE latex, the adsorption of PAE latex is lower, and PAE latex has a smaller influence on the hydration of cement paste; the presence of superplasticizer can affect the adsorption of polymer particles on the cement; the sedimentation test results show that the presence of PC and NF can reduce the adsorption of latex particles, when the dosage of PC is more than 0.3%, the adsorption rate of latex particles is reduced significantly; when the dosage of NF is 1%, the adsorption rate of latexes is reduced less than that in the case of PC.
Dispersion and Absorption of SBR Latex in the System of Mono-Dispersed Cement Particles in Water
Authors: Shi Xiao Xin , Wang Ru , Wang Pei Ming
Published: April 2013

This paper investigates the dispersion of cement particles in water at different mix proportions using optical microscope, and the dispersion and absorption of SBR latex in the system of mono-dispersed cement particles in water using environmental scanning electron microscope (ESEM). The results show that the mono-dispersed cement can be well obtained at the water to cement ratio (mw/mc) of 10:1. The ESEM images present that SBR latex is dispersed on the surface of the cement particles as well as the solution phase. SBR latex does not prefer to be absorbed on the cement particles in spite of their opposite electric charge but chooses to be dispersed in the system proportionally. In addition, SBR particles are single-layer absorbed on the surface of cement particles in all the SBR latex to cement ratios (mp/mc). Several SBR particles absorbed on the surface of cement particle get close enough to form groups at the mp/mc of 15% and 20%. The results of this paper provide some bases for analyzing the influence of polymer on cement hydration and the microstructure formation of polymer-modified cement-based materials in a new view.
Thermodynamics of the Polymer-Concrete Interface
Authors: He Hong Zhu , Cui Yu Li , Shi Mei Lun
Published: April 2013

Property of polymer-concrete in the interface has been dealt with from the view of thermodynamics. Gibbs function or free enthalpy was applied to characterize the binding ability of the interface. AC impedance spectroscopy was used to measure the electrical capacitance of the interface between the polymer particle and mortar. Lippmann equation was used to estimate the thermodynamic functions for the estimation of the binding ability. A typical example was given.
UIR-Scanner Potential to Defect Detection in Concrete
Authors: Garbacz Andrzej , Piotrowski Tomasz , Zalegowski Kamil , Adamczewski Grzegorz
Published: April 2013

In the research three NDT methods: indirect Ultrasonic Pulse Velocity, Impact-Echo (IE) and Ground Penetrating Radar (GPR) were used for investigation of concrete slabs with well-defined reinforcement and artificial defects. The obtained results shows the big potential of combination of UPE, IE and GPR methods for detection of wide range of defects in concrete structures. These methods were implemented for UIR scanner development – NDT system which accelerate assessment of concrete structure. Moreover, when the result of one method is not clear and individually the method seems to be not effective, the data from the other one allows for proper interpretation of concrete integrity.
Innovations Based on PCC
Authors: Dimmig-Osburg Andrea
Published: April 2013

Abstract. In this paper, three examples for the application of PCC are presented, which exceed the well established use as restoration material and show the great innovation potential of these materials. The first example shows an innovative development of a polymer-modified self-compacting concrete (SPCC) for the restoration of vertical facing concrete surfaces. In the second example PCC was for the first time applied as construction concrete to a bridge building. The last instance describes the potential of the SPCC for special applications in mechanical engineering. A styrene acrylic ester dispersion and different sorts of cement were used. The polymer/cement-ratio varied from 0.05 to 0.10. The water/cement-ratio depended on the requirements of the different PCC. The essential laboratory and field tests as well as the results are described.
Durability of Polymer Modified Repair Mortars on Concrete Structures
Authors: Tchetgnia Ngassam Inès Leana , Marceau Sandrine , Chaussadent Thierry
Published: April 2013

Polymer modified mortars (PMM) used as repair products present higher intrinsic properties than classic mortar due to polymer effect in the cementitious matrix. But evolution of their adhesives properties is not well known. This article deals with adhesive behavior of two PMMs made in laboratory with styrene acrylate (SA) and ethylene vinyl acetate (EVA) polymers. It is highlighted that adhesion of these mortars depends on polymer amount in the mortar, on the environmental conditions, and on the roughness of the concrete support. This adhesion is improved in warm environment and with high roughness of support surface. The influence of polymer amount is not the same for the two types of polymers but in the two cases, bond strength remains low when low amount of polymer are added.
A Study of Effectiveness of Fiber Reinforced Polymer (FRP) System on the Performance of Concrete Beams and Columns
Authors: Lu Jin Ping , Wijaya Sherly
Published: April 2013

The durability of marine concrete structures has long been a concern of many countries, especially in the island country of Singapore, where many structures are constructed along coastal areas. Currently, the durability of concrete under marine conditions can be enhanced by the addition of admixtures, and using high grade concrete. The FRP system can also be used to increase the durability of the concrete structures under marine conditions, by preventing the ingress of chloride ions into the structures, thereby preventing the corrosion of the steel reinforcements. In addition, the FRP system has the additional function of increasing the strength of the structure. The FRP system, which composed of the epoxy developed and carbon fiber selected in our previous paper [7], was evaluated according to various standard testing methods to get the basic technical information of the FRP system. Concrete beams and columns were wrapped with the FRP system in different design and tested to verify the effectiveness of FPR wrapping. The results showed that the performance of concrete specimens wrapped with FRP system developed could be increased up to 6 times compared to control specimens without wrapping.
Needed Research for Further Enhancing the Dielectric Properties of Polymer Concrete
Authors: Gunasekaran Muthian
Published: April 2013

During the past four decades, starting with the pioneering R&D work at Westinghouse in the 1970s, considerable work has been done, especially in the USA, on the dielectric properties and long-term performance of specialized polymer concrete composites for applications in the electric power industry. Polymer concrete is now well-established as a viable technical alternative to standard electrical porcelain. Its energy efficiency, its low cost, its universal processability at ambient temperature, and its design versatility have now spawned a wide variety of successful applications world-wide. Post insulators up to and including 138 kV, pin insulators, integrally cast instrument and potential transformers, various kinds and sizes of bushings, surge arresters, bus ducts, third-rail insulators in transportation, etc, are just some of the products operating successfully in the field to-day.The full potential of polymer concrete as a dielectric material has not yet been reached. With some thoughtful and functionally directed research on the properties and processing of polymer concrete, it is felt that significant advances can be made in the capabilities of dielectric polymer concrete.These advances can revolutionize the design and operation of electric power systems in the 21st century when the demands of the environment and the constraints of cost of new Ultra High Voltage power systems will be important factors governing the choice of materials. This paper gives a brief over-view of the state-of-the-art of polymer concrete dielectrics and discusses some of the needed research to meet the new challenges facing the electric power industry.
Fractionated and Recombined Casein Superplasticizer in Self-Leveling Underlayments
Authors: Bian Hang , Plank Johann
Published: April 2013

Individual casein biopolymers have been fractionated out of the whole bovine casein, and characterized with respect to their specific dispersing performance in cement based self-leveling underlayments (SLUs). In contrast to β- and κ-caseins, α-casein provided excellent dispersing effectiveness as well as unique self-healing effect on the surface of the grout. In order to reproduce the bovine casein, a reconstituted casein sample was prepared by blending the individual biopolymers. Using fast protein liquid chromatography (FPLC), the biochemical composition of recombined casein was determined. Compared with the commercial casein, the reproduced casein superplasticizer exhibited improved dispersing power in SLU paste at the flow time of 0 – 20 min. Furthermore, atomic force microscope (AFM) images revealed the morphology of commercial casein and reproduced casein in alkaline environments. The latter was found to form smaller structure, which explained the improved initial flow of SLU paste. This study suggests that the performance of casein superplasticizer can be modified by recombining the individual casein biopolymers. SLU pastes with different properties may be further achieved by adjusting the biochemical composition of the recombined casein superplasticizer.
Report from 13th ICPIC and 7th ASPIC: New Trends on Concrete-Polymer Composites
Authors: Aguiar José Barroso , Özkul Hulusi , Cunha Sandra
Published: April 2013

The field of polymers in concrete is consolidated in the construction industry. The future of polymers in concrete is governed by the synergic interaction between these materials, in order to contribute significantly towards a more sustainable construction. Concrete-polymer composites (C-PC) have excellent mechanical and durability properties. Appropriate combination of polymers and classical construction materials provides opportunities for innovative applications and systems. This paper highlights the innovations and new approaches presented at the 13th International Congress on Polymers in Concrete in Madeira, Portugal, 2010 and at the 7th Asian Symposium on Polymers in Concrete in Istanbul, Turkey, 2012. The new trends presented are related with the micro and nanostructure, properties, test methods and applications of concrete-polymer composites.
Flexure Behaviour the Concrete Beams Reinforcement with Polymer Materials
Authors: Kabashi Naser , Krasniqi Cenë , Muriqi Ali
Published: April 2013

Improvement of flexure behavior using the polymer materials is one of the very important factors in analyzing the concrete elements, especially concrete beams. In this case we analyze two different cases: • Improvement using the polypropylene microfibers in ready mix concrete • Improvement using the carbon fibers in external reinforcement In both case studies we used three-point-load experimental beam-bending tests for: three conventional RC beams (referent beams), three RC beams with polypropylene fibers and three RC beams with carbon fibers. All results concern comparing the effect of fibers on improvement of energy capacity of concrete elements, and increasing the bearing capacity of concrete beams. One of the most important values based on the behavior of the structure is ductility. The ductility is a structural design requirement in most design codes. The traditional definition of ductility cannot be applied in structures reinforced with FRP reinforcement. Several methods, such as the energy based method and the deformation based method have been suggested to calculate the ductility index for FRP reinforced structures. Furthermore the behavior of RC beams is analyzed with the help of cracks, their position and width under the loads.
Polymer Based Treatments Applied on Recycled Concrete Aggregates
Authors: Spaeth Valerie , Djerbi Tegguer Assia
Published: April 2013

The recycling of concrete, bricks and masonry rubble as concrete aggregates is an important way to contribute to a sustainable material flow. However, there are still various uncertainties limiting the widespread use of recycled concrete aggregates (RCA). The fluctuations in the composition of grade recycled aggregates and their influence on the properties of fresh and hardened concrete are of particular concern regarding the use of RCA. So, the reuse of RCA is still limited. That’s why an efficient polymer based treatment is proposed in order to reuse RCA easier.
Manufacture of Lime Mortars for Restoration with Addition of Polyamide Powder Waste
Authors: Garabito J. , Rodríguez A. , Gutierrez S. , Calderón V.
Published: April 2013

We use lime mortar in historic building’s interventions instead of cement mortars, due to its better compatibility with the masonry walls. The objective of the present research is to examine the behavior of a traditional lime mortar by the addition of polyamide powder waste. In certain circumstances we need to improve the mortar properties, such as increasing its impermeability while maintaining its breathability. This happens when we need to coat the filling of a stone wall that has been exposed to the outside. First of all we study the properties of a traditional lime mortar, as a reference. Then we replace aggregates using polyamide powder waste with different dosages. Subsequently we carry out some studies on the resulting mortars, through a series of tests, such as water vapour permeability and water absorption capacity through capillarity. Finally we check if the hydrophobic behavior improves, while maintaining the capacity of vapour transpiration.
Novel Core-Shell Hybrid Polymers Designed as Dual Functional Additives for Concrete
Authors: Pavlitschek Thomas , Gretz Markus , Plank Johann
Published: April 2013

Novel hybrid admixtures for construction applications were prepared by layer-by-layer deposition technique. Colloidal core templates consisting of styrene/n-butylacrylate latex particles were coated with multilayers of superplasticizers commonly used in concrete. This way, core-shell particles possessing both dispersing and film-forming properties were achieved. Incorporation of the latex@dispersant hybrid additive into a cement paste results in a slow release of the superplasticizer as a result of gradual shell disintegration which instigates prolonged plastification (long ”slump life”) of the cement slurry. Once the shell has been dissolved, latex particles are released into the pore solution and can coalesce into a polymer film which improves the mechanical properties of the hardened cement. Characterization of the templates and novel additives was performed by means of zeta potential measurement, dynamic light scattering and electron microscopy. Our method allows to synthesize multifunctional additives with time-controlled release effect.
The Study of a New Synthesis Method of Isoamyl Enol Polyoxyethylene Ether and its Compatibility on Cement
Authors: Xiao Li Guang , Yan Cun You , Zhang Shi Ting
Published: April 2013

In this study, a kind of water reducing agent based on Isoamyl enol polyoxyethylene ether were synthesized in water solution by radical copolymerization. The influence of copolymerization conditions on dispersing performance of the water reducing agent in the cement was investigated. The molecular structure of the copolymer was tested by NMR, and GPC was used to determine the molecular weight of copolymer and the big monomer percent conversion, also, testing the adaptability of the water reducing agent in different types of cement. The testing results show that the water reducing agent has the good performance on concrete. When the dosage of water reducing agent was 0.2%, the (Deer ding card, P.O42.5) slurry flow degree of the cement was 270mm, and the water reducing ratio reached 19.6%. When the dosage of water reducing agent was 0.3% and 0.4%, the water reducing ratio reached to 28.6% and 31.9% respectively. Comparing the adaptability of the water reducing agent on all kinds of cement, the water reducing agent performed the worst in the P.C cement and better in the P.O cement, its adaptability in the standard cement and P.S cement was the best. When the dosage of water reducing agent was 0.2%-0.4%, the water reducing ratio was nearly the same, When the dosage of water reducing agent was 0.4%-0.6%, the water reducing ratio in the standard cement was higher than in the P.S cement.
The Preparation and Characterization of Redispersible Polymer Powder with Core-Shell Structure
Authors: Xu Jian , Feng Zhong Jun , Fu Le Feng , Zheng Bai Cun
Published: April 2013

Acrylate polymer emulsion was synthesized by semi-continuous seeded emulsion polymerization with methacrylic acid (MAA) as the hydrophilic shell monomer. The redispersible polymer powder was prepared by spray drying method. The effects of the amount of MAA, styrene (St) stoichiometry equivalents to methyl methacrylate, and two kinds of spray drying methods on size distribution of the redispersible polymer powder were further systematically investigated. The Malvern laser particle size analyzer, transition electron microscopy (TEM), scanning electron microscopy (SEM) and differential scanning calorimeter were employed to characterize the redispersible polymer powder. Results showed that the redispersible polymer powder obtained by pneumatic spray drying with excellent re-dispersibility could be synthesized at 10 % of MAA, 50 % of St stoichiometry equivalents. The final copolymer emulsion with “perfect” core-shell morphology was approved by TEM, and the comparable film forming ability of the redispersible polymer powder with the original emulsion was observed by SEM, which could form a dense and smooth membrane.
Novel Epoxy-Silica Hybrid Adhesives for Concrete and Structural Materials: Properties and Durability Issues
Authors: Frigione Mariaenrica , Lionetto Francesca , Mascia Leno , Antonacci Antonio
Published: April 2013

Novel epoxy-silica hybrid systems based on silane-functionalized epoxy resins containing interpenetrating silica domains were investigated as structural adhesives with the aim to achieve a good retention of properties when the adhesives are exposed to severe environmental conditions or weathered. Durability experiments have been conducted on the experimental hybrid adhesives by monitoring their mechanical properties, on both cast specimens and on adhesive joints composed of cylindrical concrete or masonry blocks, in ordinary conditions or after exposure to different environmental agents (moderate temperature, immersion in water, outdoor exposure).
Antibacterial Applications of Silver Nanoparticles
Authors: Pattabi Rani M. , Pattabi Manjunatha
Published: April 2013

A brief review on the antimicrobial application of Ag nanoparticles (AgNP) is presented. Ag in nanoform is considered less toxic than Ag+ ions and hence, a considerable amount of research has been carried out on the antibacterial, antifungal and antiviral activities of Ag nanoparticles. Poly (vinyl alcohol) (PVA) stabilized AgNPs provide overwhelming evidence on their potency against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Streptococcus pneumonia etc. A recent study using biostabilized AgNPs have shown their efficacies against a vast range of bacteria. The antibacterial activity of AgNPs has also resulted in the development of wound dressings and medical devices. Some results on the antifungal activities exhibited by them are also highlighted.
A Novel Sonochemical Synthesis of Metal Oxides Based Bhasmas
Authors: Sivasankaran S. , Sankaranarayanan S. , Ramakrishnan S.
Published: April 2013

Metal oxides form part of inorganic medicines called Bhasmas, which has been used in a non-allopathic medicine system practiced in India called Ayurveda. Bhasmas may be classified under the nanomedicines of ancient India. The traditional preparation methods involve time consuming and complicated preparation procedures. This paper highlights a novel ultrasound assisted technique called sonochemical synthesis of transition metal oxides in a facile, faster, inherently safer and environmentally benign (green chemistry) way which could be considered to be used for the synthesis of metal oxides such as copper oxide which form part of the copper based Ayurvedic nanomedicine called tamra bhasma, which is copper in its oxide form and used therapeutically as a source of copper. The synthesis procedure outlined here could be considered for the preparation of other types of Bhasmas also.
Recennt Advances on Chitosan-Metal Oxide Nanoparticles and their Biological Application
Authors: Sunil Dhanya
Published: April 2013

There is a growing interest in the use of green resources for nanoparticle (NP) synthesis. Natural polymer, Chitosan (CH) has been employed as templates for the preparation of metal oxide NPs. They modify the surface characteristics of the nanometal oxides generated. In the presence of template CH, the spatial separation of the particles, enable the synthesis of highly crystalline, mono-dispersed particles of < 100 nm. The properties of metal oxides can be improved by combining with CH and the product can be employed for different applications. CH along with metal oxide NPs has recently been utilized as a stabilizing agent due to its excellent film-forming ability, mechanical strength, biocompatibility, non-toxicity, high permeability towards water, susceptibility to chemical modification and cost-effectiveness. Metal oxide NPs-CH based hybrid composites have attracted much interest for the development of desired biosensors, MRI agents, buffers, antibacterial agents etc.
Characterization of the Thermoelectric Behavior of Plastically Deformed Steels by Means of Relative Seebeck Coefficient
Authors: Demmel Peter , Tröber Philipp , Kopp Thomas , Golle Roland , Volk Wolfram , Hoffmann Hartmut
Published: April 2013

The thermoelectric phenomenon can be used for a wide application spectrum. Typically, the Seebeck effect of metallic materials is used for temperature measurement in common thermocouples. However, there is also a high potential for adapting the effect in nondestructive testing due to a high sensitivity of the thermoelectric properties to a variety of material characteristics.Different studies point out an influence of plastic deformations on the thermoelectric behavior of metals, but a detailed and quantitative analysis and description is not provided yet. There is an increasing interest in detecting the changes of properties by nondestructive characterization of plastically deformed materials. Especially in metal forming, the knowledge about the correlation between the degree of deformation and the thermoelectric behavior can help to check formed metal parts. On that account, the influence of plastic deformations on the thermoelectric behavior, in particular the Seebeck coefficient, of four steel alloys is introduced in this paper.An apparatus based on the integral measuring method was built up to measure the relative Seebeck coefficient to a reference material at different temperature gradients and for several degrees of plastic deformation. Well defined values of plastic deformation are realized by cold rolling. With this compressive forming technology a logarithmic deformation φ up to 2.11 was set for all steel alloys. Besides a high degree of deformation, a uniform strain over the sample thickness can be obtained by rolling.With increasing plastic deformation a significant change of the relative Seebeck coefficient can be observed in a defined temperature range for all investigated steels. The plastic deformation is accompanied by an increase of dislocation density into the lattice structure of the metal. These line defects provoke the formation of new scattering centers and thus the electron motion is disturbed. By the combination of metallurgical examinations and measurements of micro hardness, the relation between the thermoelectric behavior and the plastic deformation of steels can be clearly illustrated.
Microporous Carbonaceous Materials Incorporated with Metal (Ti, V and Zn) for Hydrogen Storage
Authors: Nath Mala , Kumar Asheesh , Mallick Arijit
Published: April 2013

The present research work is focused on the development and characterization of light weight microporous carbonaceous material, such as graphite (53150 micron) incorporated with either titanium n-butoxide, titanium diisopropoxide bis (2,4-pentanedionate), vanadium 2,4-pentane-dionate or zinc 2,4-pentanedionate having varying wt% of the metal (28%) using 2-propanol/ethanol as solvent at 4050 °C. The calcination has been carried out at 100, 150 and 200 °C, except the samples with titanium diisopropoxide bis (2,4-pentanedionate) which are calcined at 80 °C. FESEM along with atomic absorption studies revealed that the maximum incorporation of metals (Zn, V and Ti) in graphite has been observed with 4 wt% of zinc 2,4-pentanedionate calcined at 100 °C, 4 wt% of vanadium 2,4-pentanedionate calcined at 100 °C, 4 wt% of titanium n-butoxide calcined at 100 °C and 2 wt% of titanium diisopropoxide bis (2,4-pentanedionate) calcined at 80 °C, and equilibration time of 20-24 h has been used in each case. These samples may be used for hydrogen storage.
Electrochemical Characterization of the Structural Metals Immersed in Natural Seawater: In Situ Measures
Authors: Galván-Martínez Ricardo , Cabrera de la Cruz David , Galicia-Aguilar Gonzalo , Orozco-Cruz Ricardo , Contreras-Cuevas Antonio
Published: April 2013

This work presents the electrochemical corrosion results of the structural metals, aluminium (Al), brass and copper (Cu), immersed in coastal waters of Veracruz Port in Mexico at room temperature, atmospheric pressure and eight weeks of the exposition time. The electrochemical technique used was electrochemical noise (EN). A typical three-electrode electrochemical cell was used. Where the reference electrode was the silver/seawater (Ag/SW) and two nominally identical metallic samples were used as working electrodes (WE1 and WE2). The metallic samples of Al, brass and Cu were used as working electrode. The potential and current fluctuations were measured simultaneously between the two working electrodes (current measured) and the Ag/SW electrode (potential measured). The electrochemical noise measurements (ENM) were analysed by three different methods: Potential and current versus time (transients), Localization Index (LI) and Electrochemical Noise Resistance (Rn). The results shown a good correlation between the superficial analysis and the results obtained by the ENM. In addition, Cu presents the highest corrosion rate and, a corrosion attack was obtained by localization index; this behaviour was confirmed by superficial analysis.
Multilayered Zircon-Alumina Components Fabricated by Slip Casting
Authors: León-Carriedo M. , Gutiérrez-Chavarría Carlos A. , Rodríguez-Galicia Jose Luis
Published: April 2013

In recent years there have been many studies attempting to increase the mechanical properties and reliability of structural ceramic materials; the forming methods used for this purpose are based on multi-layered materials to induce residual stress between interface layers. In this work were made monolithic and multi-layered materials manufactured by casting in plaster of Paris molds using zircon and alumina as raw materials, mechanical and microstructure characterizations were compared, founding that, indeed, the laminar designs can substantially improve the mechanical properties of manufactured materials by the compressive stress between the interface layers.
Electrochemical and Tension Tests Behavior of API 5L X60 Pipeline Steel in a Simulated Soil Solution
Authors: Quej-Aké Luis M. , Galván-Martínez Ricardo , Contreras-Cuevas Antonio
Published: April 2013

In this work electrochemical impedance spectroscopy (EIS) and slow strain rate tests (SSRT) were used for the evaluation of API 5L X60 carbon steel in contact with a simulated soil solution called NS4. EIS monitoring before and after performing the tension tests was carried out. SSRT were carried out in NS4 solution at room temperature to simulate dilute ground water that has been found associated with stress corrosion cracking (SCC) of low carbon steel pipelines. A strain rate of 1x10-6 sec-1 was used. According to the analysis of SSRT, the X60 pipeline steel is highly resistant to SCC. In order to perform the electrochemical test, two working electrodes were considered, a complete specimen, before the SSRT and a fractured specimen after the SSRT. The analyses of results show that the electrochemical response was different in each samples. The corrosion rate (CR) obtained by the two corrosion techniques revealed that the CR of the fractured specimen was higher than the CR of the complete specimen. This behavior is attributed to the fact that the fractured specimen present a high degree of tortuosity and this condition activate the corrosion process. In addition, according to the cathodic Tafel slope, the reduction reacction was influenced by a difusion process. A combine fracture type in SSRT was observed: ductil and brittle with a transgranular appearance. Some pits and internal cracks close to the fracture zone were observed. The failure process and mechanism of X60 steel in NS4 solution are controlled by dissolution and hydrogen embrittlement.