References Wkx
Beach, E., Tormoen, G., Drelich, J. Pull-off forces measured between hexadecanethiol self-assembled monolayers in air using an atomic force microscope analysis of surface free energy. Journal of Adhesion Science and Technology 16 7 , 845-868 2002 Du, B., Tsui, O., Zhang, Q., He, T. Study of Elastic Modulus and Yield Strength of Polymer Thin Films Using Atomic Force Microscopy. Langmuir 17 11 , 3286-3291 2001 Frisbie, C.D., Rozsynai, L.F., Noy, A., Wrighton, M.S., Lieber, C.M. Functional Group...
Introduction Dwo
Atomic force microscopy and nanoindentation are relatively new techniques for materials characterization. An AFM measures the surface roughness and adhesion force, whereas the nanoindentation measures the modulus and hardness of a material. Although application of these two techniques are not much yet in civil engineering, they are being widely used in sister disciplines such biomedical, aerospace, manufacturing, materials, physics, chemistry, and electrical engineering. In other disciplines,...
Introduction Taf
When talking about nanotechnology and cementitious systems it is not always easy to span the bridge between modern advanced technology and know how which exists since some two thousand years. But it is always good to start from BASF SE, Polymer Research, Physics for Polymer Systems, BASF Construction Chemicals GmbH, Polymer Research, Mineralogy, BASF Construction Chemicals GmbH, Polymer Research, Mineralogy, K. Gopalakrishnan et al. Eds. Nanotechnology in Civil Infrastructure, pp. 175-205....
References 1
Addis, B.J. Fulton's Concrete Technology. Portland Cement Institute, Midrand, South Africa 2001 Balazs, A.C. Modeling self-healing materials. Materialstoday 10 9 , 18-23 2007 Ballari, M.M., Hunger, M., Husken, G., Brouwers, H.H. Heterogeneous photocatalysis applied to concrete pavement for air remediation. Nanotechnology in Construction 3 2009 Barstis, W.F., Crawley, A.B. The use of fly-ash in highway construction. Report 84-DP59- MS-05, Mississippi Department of Transportation, Jackson, MS...
Nanoclays in Asphalt Binders and Mixtures
Pavement researchers have suggested that nanoclays have interesting performance enhancing characteristics that could improve the mechanical strength properties of both asphalt binders and mixtures. In one of such notable studies, it has been shown that polymeric nanoclay composites can improve the physical, chemical and mechanical properties of asphalt binder systems when the nanoclays are evenly dispersed at the nanoscopic level within the binder system Jahromi and Khodaii 2009 . Nanofil-15...
Incorporation of NanoSiO during Mixing
Research showed that the compressive and flexural strengths of cement mortars containing SiO2 and Fe2O3 nano-particles were both higher than those of plain cement mortar Li et al. 2004, Hui Li 2004 . The experimental results show that the compressive strengths of mortars with nano-silica NS were all higher than those of mortars containing silica fume at 7 and 28 days. An addition of 10 nano-SiO2 with dispersing agents resulted 26 increase of 28 days compressive strength whereas the increase of...
Damping Property of Nanocomposites
One of the important material characteristic needed for civil engineering structures is the ability to absorb vibrations, typically referred to as the damping capacity. Damping capacity is the dissipation of vibration by converting the mechanical energy introduced by vibration into heat. One of the materials that showed promise in this aspect is fiber reinforced materials. The ability to tailor the interface strength between the fibers and matrix enhances the ability to design for a specific...
What Is a Nanoclay Particle
Nanoclays has been defined as clay that can be modified to make the clay complexes compatible with organic monomers and polymers Jahromi and Khodaii 2009 . In striking similarity with montmorillonite clay minerals, x-ray and microscopic detailing have indicated the presence of Si, O, Mg, Al and Fe elements in typical nanoclay materials, which are small in nature and have poor crystalline shapes Ghille 2006 . Ghille further reported that nanoclays do not normally have nitrogen elements in them....
Molecular Statics
In molecular static MS modeling, energy minimizations are performed on the atomic structure as described in Leach 2001 . This minimization will yield an equilibrium structure based on the closest local minima of the initial atomic structure. However, the optimized structure, thus obtained may characterize one possible equilibrium or stable structure of the many that could exist. The bulk properties of the material like mechanical properties, vibrational properties, electrical properties depend...
CSH Understanding Using Crystal Structures
Faucon et al. 1996 used MD simulations to understand the NMR data concerning C-S-H. Using the Tobermorite structure they observed that in the absence of calcium atoms, no break in the chain is observed. The presence of Ca causes partial rupture of Si chains. Faucon et al. 1997 also showed that Al atom can be substituted in the place of Si atom. Such substitution is possible where the bridging Si is energetically less stable. Faucon et al. 1999 used the similar substitutions using Na....
Modeling to Find the Amorphous Structure of CSH
The computed bulk properties of Tobermorite crystal structure is 4 to 5 times the bulk properties of cement paste as reported by Janakiram Subramani et al. 2009 . Plassard et al. 2004 observed a bridging silicon Si atom missing in the silicate chains thereby forming dimers or pentamers. If the missing Si atom occurs after every two Si positions in the chain it is called a dimer whereas if the missing Si atom occurs after every five Si positions in the chain it is called a pentamer. To verify...
Selfsensing Concrete Structures
2.4.1 Preparation of Concrete Column with Embedded CBCC Sensor Epoxy encapsulated CBCC sensor with shape of 30x40x50 mm was prepared with the developed methods, and the properties of CBCC sensor were shown in table 1. Resistivity , , Gage factor iicm Concrete columns were made with C40 and C80 concrete respectively for the aim of studying the strain sensing property of CBCC sensors in different strength grades of concrete matrix. The cement used for C40 and C80 concrete were Portland cement...
Reinforcements of NanotubesNanofibers
Carbon nanotubes nanofibers CNTs CNFs are potential candidates for use as nano-reinforcements in cement-based materials. CNTs CNFs exhibit extraordinary strength with moduli of elasticity in the order of TPa and tensile strength in the range of GPa, and they have unique electronic and chemical properties Ajayan 1999, Salvetat et al. 1999, Srivastava et al. 2003 . Cementitious materials e.g., concrete are typically behave as brittle materials with low tensile strength and prone to crack....
Introduction Msz
Concrete is used extensively in constructions for buildings as well as in highways. The durability and long life-cycle of concrete is affected by minute cracks due to shrinkage and load-related stress. This is due to the relative lack of tensile strength compared to the compressive strength of concrete. Cement pastes which exhibit BELL 4190 University of Arkansas, Fayetteville, AR 72701, USA e-mail rps uark.edu BELL 4190 University of Arkansas, Fayetteville, AR 72701, USA e-mail kdhall uark.edu...
Optimization of Clay Addition for the Enhancement of Pozzolanic Reaction in
Abstract. This chapter presents a process for obtaining nano-size silicate platelets for use in cement paste from exfoliating Cloisite Na clay particles. The resulting silicate platelets require all surface electrical charges to be neutralized. The results showed that this is achievable through the use of organic ammonium chloride surfactant. The exfoliation process was evaluated through the use of X-ray diffraction and the optimum stable concentration of organic ammonium chloride was...
Flexural Fatigue Performance of Concrete Containing Nanoparticles for Pavement
3.3.1 Materials and Mixture Proportions The materials and fabrication methods were same to that shown in section 2.2. Six kinds of mixtures are cast in this study. The water binder ratio used for all mixtures is 0.42, where the binder weight is the total weight of cement and nano-particles. Sand ratio is 34 . The mixture proportions for cubic meter of concrete are given in Table 12. Herein, PC denotes plain concrete. PPC denotes the concrete containing PP fibers in the content of 0.9 kg m3....
Dispersion and Morphological Characterization of the Nanoclaymodified Asphalt
3.2.1 Dispersion Characterization Separation Tube and X-Ray Dispersion After the preparation of the Nanomer and Cloisite-modified PG 64-28 asphalt binders, two techniques are employed to evaluate the extent of dispersion of the Nanomer and Nanocloisite particles within the PG 64-28 asphalt binder system. The two techniques are the separation tube method and the X-ray dispersion method XRD . The separation tube method involves the application of a thin-walled metal tube used to ascertain the...
Characterization of the NanoclayModified Asphalt Binder
Based on the Superpave Standard Specifications for testing asphalt binders, the under-listed test procedures were conducted on both the control and the four nano-clay modified asphalt binders a Rotational viscosity test RV - Standard Method for Viscosity Determinations of Unfilled Asphalts Using the Thermosel Apparatus, ASTM 4402 . b Dynamic shear rheometer test DSR - Rheological Properties of Asphalt Binder Using Dynamic Shear Rheometer AASHTO TP5 c Rolling thin film test RTFO - Standard...
Characterization of Asphalt Materials for Moisture Damage Using Atomic Force
Abstract. Asphalt materials have traditionally been characterized for moisture damage at component microscale and laboratory specimen macro scales. Though characterizations at such scales are commendable and often necessary and well understood by the pavement engineering community, there are problems which cannot be solved using micro and macroscale characterizations. For example, moisture damage in asphalt pavement is caused by moisture interaction with asphalt-aggregate bonds, which occurs at...
Reactive Powder Concrete RPC
A process for synthesis of cement with nano-scale particle sizes has recently been developed. It is demonstrated that nanocements with nano-scale particle sizes and varying phase compositions can be tailored. Addition of nano-cement in reactive powder concrete RPC systems has the potential to further enhance the properties of an already optimized system. The replacement of a small fraction of the conventional cement with these nano-cements causes faster cement hydration reaction and reduces the...
Pavements and Nanotechnology
Chemistry is the science concerned with the composition, structure, and properties of matter, while physics is the science that deals with concepts such as force, energy, and mass with the goal of understanding the natural world. Engineering seeks the creative application of scientific principles to design, develop, manufacture and operate structures, machines, manufacturing processes or works while acknowledging issues around economics of operation and safety to life and property. Pavement...
References Sjl
1. Scott, W.D., Charles, R.F., Michael, B.P., Daniel, W.S. Damage Identification and Health Monitoring of Structural and Mechanical Systems from Changes in Their Vibration Characteristics A Literature Review 1996 Report of Los Almos Lab 2. Chen, J.C. Intelligent Monitoring System for Suspension Bridge Damage Detection. In Proc. of Bridge into the 21st Century Conference, Hongkong October 25, 1995 3. Li, H., Ou, J.P., Zhao, X.F. Structural health monitoring system for the Shandong Binzhou Yellow...
Introduction
Many civil infrastructures around the world are in a state of utter disrepair, and significant efforts are needed to render the failing infrastructures back to a serviceable and safe state. The root of the problem is at the apparent lack of durability in construction materials, inability to provide timely maintenance, absence of School of Civil Engineering, Harbin Institute of Technology, Harbin, 150090 China e-mail hithanbaoguo china.com.cn, baohan d.umn.edu Department of Mechanical and...
Abrasion Resistance of Concrete Containing Nanoparticles 321 Materials and
The cement used is Portland cement P.O42.5 . Fine aggregate is natural river sand with a fineness modulus of 2.4. The coarse aggregate used is crushed diabase with diameter of 5 25mm. UNF water-reducing agent one kind of P -naphthalene sulfonic acid and formaldehyde condensates, China is employed to aid the dispersion of nano-particles in concrete and achieve good workability of concrete. The defoamer, tributyl phosphate made in China is used to decrease the amount of air bubbles. The...
Nano Clay Composite
Nanoclay particles have shown promise in enhancing the mechanical performance, the resistance to chloride penetration, and the self-compacting properties of concrete and in reducing permeability and shrinkage Chang et al. 2007, Kuo et al. 2006, Morsy et al. 2009, He and Shi 2008 . Organo-modified montmorillonites OMMT which have been widely used in polymer clay nano-composites PCN are employed as fillers and reinforcements in cement mortars Kuo et al. 2006 . The hydrophilic montmorillonite MMT...
Preparation of the Nanoclay Compound
Surfactant-modified nanoclay A and B was first dispersed in isopropanol, a known organic solvent. The Nanoclay A and B were Nanomer and Nanocloiste nanoclay materials, respectively. Silane coupling agent was added to the surfactant-modified nanoclay and the mixture was continuously stirred in a water bath until all of the solvent evaporates. The use of a silane coupling agent has been known to contribute significantly towards the production of a homogenous uniformly dispersed nanoclay compound...
Improved Materials
Nanotechnology partly focuses on the creation of new materials at the molecular level with significantly improved properties on the mechanical and related levels Chong 2003 . Through judicious application of nanotechnology techniques material behavior problems can be addressed through engineering techniques on the nano-scale. This allows the molecular properties of materials to be better understood, and the molecular properties of materials to be changed, leading to improved behavior of the...
Design of CSH Nucleation and Growth
The most exciting cement mineral and which has also led to the largest collection of work is undoubtedly C-S-H. Unfortunately this hydrate is difficult to characterize and to quantify during the cement hydration. These problems were and are still basically the greatest barrier to overcome in order to perfectly seize the link existing between the development of this hydrate and all the mechanical changes occurring in a cement paste. The lack of investigation techniques was at the origin of many...
Dynamic Shear Rheometer DSR
In Fig. 5 and 6, two bar charts showing the DSR trends are presented here to establish the rheological characteristic of the original and nano-modified PG 64-28 asphalt binder systems. With 2 and 4 nanoclay addition to the PG 64-28 asphalt binder, the G value increased by an average of 66 and 125 , respectively, from that of the original heat mixed PG 64-28 asphalt binder. When 2 of Nanoclay B was added, the trend showed an average G increase of 184 while increasing the Nanoclay B additive to 4...
Infrastructure
Nanotechnology in Civil Infrastructure Kasthurirangan Gopalakrishnan, Bjorn Birgisson, Peter Taylor, and Nii O. Attoh-Okine Eds. Nanotechnology in Civil Infrastructure Prof. Dr. Kasthurirangan Gopalakrishnan Department of Civil, Construction and Swedish Royal Institute of Technology ISBN 978-3-642-16656-3 DOI 10.1007 978-3-642-16657-0 Library of Congress Control Number 2011922618 2011 Springer-Verlag Berlin Heidelberg This work is subject to copyright. All rights are reserved, whether the whole...
Preface
Nanotechnology was conceived with a vision to advance our understanding and control of matter at nanoscale toward national economic benefit, national and homeland security, and improved quality of life. It enables changes at the molecular level to optimize material behavior and performance of civil infrastructure systems such as buildings and highways at the macro-functional level. The resulting nano-modified high-performance construction materials and systems are characterized by higher...
Application of Nanoscience Modeling to Understand the Atomic Structure of CSH
R. Panneer Selvam, Kevin D. Hall, Vikramraja Janakiram Subramani, and Shanique J. Murray Abstract. Concrete is used extensively for constructing buildings and highways. In order to enhance macroscopic mechanical properties tensile strength it is necessary to understand the structure and behavior of C-S-H gel at the atomic level. Current status in nanoscience modeling of C-S-H is reviewed. The computational tools available and their limitations are also surveyed. Application of nano science in...
References
Aitcin, P.C. Cements of yesterday and today Concrete of tomorrow. Cement and Concrete Research 30, 1349-1359 2000 Azhari, F. Cement-based sensors for structural health monitoring. Dissertation for the Master Degree of Applied Science. University of British Columbia, Vancouver, Canada 2008 Banthia, N. Fiber reinforced concrete for sustainable and intelligent infra structure. In First International Conference on Sustainable Built Environment Infrastructures in Developing Countries, Algeria, pp....
Multifunctional and Smart Carbon Nanotube Reinforced CementBased Materials
Abstract. Nanotechnology has changed and will continue to change our vision, expectations and abilities to control the material world. These developments will definitely affect the field of construction and construction materials. Carbon nano-tubes CNTs are considered to be one of the most beneficial nano-reinforcement materials. The combination of high aspect ratio, small size, low density, and unique physical and chemical properties make them perfect candidates as reinforcements in...