Flexible Repair Adhesive: Fill & Download for Free

“ Marine Sealants - All You Need To Know - Boat Renovation People ““ Knowing The DifferenceAn adhesive sealant can be used to seal fittings but also has adhesive properties so it can mechanically bond to certain materials. In short, you could stick your friends bum to a chair using it, but the prank may take up to 24 hours as it can take a long time to cure.A non-adhesive sealant will generally rely on the aid of a fitting, screw or bolt to create a waterproof seal. With a normal sealant, you are essentially creating a waterproof gasket. You can’t rely on normal sealant to hold anything in place; you are relying on a method of fastening, for example; a screw or bolt.Types Of SealantSiliconeButylHybrids (using the best elements to create better products)PolysulphidesPolyurethaneSiliconeIt is said that silicone is an inert synthetic polymer compound and is technically part of the rubber family. You can imagine why its been a favourite in boat maintenance for some time. Its UV resistant, heat resistant, a great insulator and is ideal for creating gaskets. Its downfall is that it makes for a weak adhesive and for this reason sometimes is unpractical for use below the water line.HybridHybrids are combinations of the best elements of existent sealers. The idea being that each type of sealant has it’s pros and cons so they just pick the pros from the best types. For example the strength of polyurethane with the UV heat resistance of silicone. They will bond better but aren’t as strong as polyurethane.PolyurethanePolyurethane sealants create an extremely strong mechanical bond when used on the correct surface. They are UV resistant and can be used below the waterline. In the aviation industry on unpressurized aircrafts, windows are sometimes attached using adhesive sealant only. This is a testament to the strength of modern sealants. It’s notable that polyurethane is not compatible with acrylic perspex and other types plastic glazing.PolysulfidesPolysulfides; a synthetic rubber, forms a strong mechanical bond and has an excellent resistance to UV, fuel and oil as well as good general corrosion protection. Polysulfide also makes a great electrical insulator and is resistant to vibration, shock, impact, and thermal changes. It can be easily painted.ButylButyl is a non-adhesive sealant normally found in the form of tape and has the characteristics of chewing gum, but can now be purchased as sealant. It’s great for serviceability and it’s easy to remove and re-apply as well as being a lot less messy than traditional sealants. It could last 20 years but it won’t look great. It’s susceptible to UV damage and can often look like a bit of old chewing gum. It’s not suitable for use below the waterline.POPULAR MARINE SEALANTSBostik Simson ISR 70-03 – £10 inc shipping – Sealant And Mild AdhesiveISR 70-03 is a high-grade, one component, silyl modified polymer marine grade sealant that has been specially formulated for the rough and tumble of industrial environments. It’s fast, strong and elastic properties make it ideal for sealing deck equipment. This sealant also adheres to the majority of surfaces used in boat building including aluminium, stainless steel, brass, powder coated surfaces, galvanised steel, copper, most lacquered surfaces, glass, brass, powder coated surfaces, zinc, polyester and grp and most impressively Lacquered wood.Tensile Strength – 2.6 MPa.Elongation Break – 250%Strong UV resistance and great ageing properties.Solvent, isocyanate and PVC free.Resistance to fresh and salt water making it ideal for use below the waterline.Fast curing.Flexible once set and permanently elasticated within temperatures from –40°C till +120°C.Can be painted wet on wet.Compatible with the majority of industrial paint coatings.Can be sanded after curing.Available in white, grey, black, dark grey, brown, yellow.Arbomast BR – £8.00 – SealantArbomast BR is a one component Butyl rubber based sealant thatcan be used for bedding deck hardware. It has mild adhesive properties. Sources have claimed it has a proven service life of 20+ years. Like other sealants, it will adhere to most construction materials and substrates. The downside is that it has low UV resistance meaning it isn’t suitable for areas exposed to sunlight.Tensile Strength -Unknown.Elongation Break – Unknown.20+ year service life.Easy applications.Available in grey, teak and black.Geocel Marine Rubber Silicone – £13 inc shp – SealantGeocel is a one component flexible silicone sealant that has been specifically formulated for a watertight seal which is resistant to the marine environment. It can also mildly adhere to GRP, most metals, glass, painted or varnished wood, and most plastics. It is particularly good for sealing around hatches and port holes, locking nuts and bolts against vibration, the insulating of electrical connectors, sealing plumbing pipework, creating in-situ gaskets and creating watertight joints throughout.Tensile Strength -2.3 MPa.Elongation Break – Unknown.High flexibility.Resistance to salt and fresh water.Resistant to high vibrations.Available in white, black, clear.Sikaflex 291i – £13 inc shp – Adhesive SealantSikaflex 291i excels in its mechanical bond strength and is a polyurethane sealant. It will bond with most of the common building materials used in boat construction and maintenance. It will bond to wood, most metals, metal primers and paint coatings (2-C systems), ceramic materials and GRP. However, it isn’t suitable for use with plastics that are prone to cracking, for example, acrylic boat windows.Tensile Strength -1.8 MPa.Elongation Break – 500%Vibration-resistant.Resistant to fresh water, seawater, limewater, sewage effluent, diluted acids and caustic solutions; temporarily resistant to fuels, mineral oils, vegetable and animal fats and oils.Not resistant to organic acids, alcohol, concentrated mineral acids and caustic solutions or solvents.Available in white, black, brown.Puraflex 40 – £8.54 inc shp – Adhesive SealantAlthough Puraflex 40 does not claim to be specifically designed for marine use, like Sikaflex its a one component polyethene with excellent mechanical resistance and bonding. Some resellers websites have claimed its use as a marine sealant as well as being backed by user testimonials on various boating forums. It can be used on concrete, wood, metal, aluminium, polyester, glass, uPVC, stone, and ceramics.Tensile Strength -1.5 MPa.Elongation Break – 700%Excellent chemical resistance.High mechanical bonding strength.Resistance to salt water.Available in white, black and grey.Aquaseal mSEAL 295 – £4.00 inc shp – Mild Adhesive SealantmSEAL 295 is one component polyurethane adhesive and sealant that prides itself on its permanent elasticated and vibration resistant properties. It will bond to most marine substrates but is however limited to use for light stress loaded bonding. Notably, it also has a slower curing time and can not be used on surfaces that bleed oils or plasticisers.Tensile Strength -1.5 MPa.Elongation Break – 600%Strong UV resistance.Silicone free.Resistant to salt water.Resistant to high vibrations.Outstanding primer adhesion to most marine substrates.Excellent adhesion to metals.Available in white and black.Evo-Stik Sticks Like Sh*t – £5.64 inc shp – Adhesive SealantEvo-Stick Sticks Like Sh*it is a high strength single component silyl modified polymer (SMP) based adhesive and can most impressively be applied to damp and even wet surfaces. This makes it a great adhesive sealant to have on board for emergency use. It can be used on a wide range of materials including wood, concrete, glass, brick, ceramics, metals, rigid PVC, plaster, grp insulation boards and foam polystyrene. Notably, it won’t bond to polyethene, polypropylene or Teflon.Tensile Strength -1.8 MPa.Elongation Break – Unknown.Stays elasticated once formed.High mechanical bond strength.Resistant to water as well as oil & petrol.Available in warm white only.UniBond FlexTec FT101 – £12 inc shp – Adhesive SealantUniBond FlexTec FT101 is a one component hybrid polymer which can be used to seal, fill and bond. It claims to be able to bond without the use of a primer to a wide range of materials but doesn’t specify which ones it does not. It can also be applied on both damp and wet surfaces but does take 24hours to set and may not ideal for fast same day repairs.Tensile Strength – 1.0 MPa.Elongation Break – 400%Easy to work with.Strong UV resistance.Available in white only.3M 4200FC – £15 inc shp – Adhesive Sealant3M 4200FC is all around one part polyurethane adhesive sealant that can be used to bond wood, gel coat and fibreglass. It can also be used above and below the waterline.Tensile Strength – 1.24 MPa.Elongation Break – 400%Fast Tack-Free time – 1-2 hours.Permanently elastic.High vibration and shock resistance.Available in white.Everbuild Stix‐All – £10 inc shp – Adhesive SealantEverbuild Stix-All is a one component adhesive sealant utilising the best elements of silicone and polyurethane technologies to create a hybrid. It hasn’t been designed for marine use specifically but It is compatible for adhering with most the common materials and can be applied on both damp and wet surfaces. It will bond to metals, plastics, glass, concrete, plasterboard, plaster, polyester, perspex, glass, wood, enamel, painted surfaces and GRP.Tensile Strength -1.5 MPa.Elongation Break – Uknown.High bonding strength.Resistant to water, petrol, 10% dilute acids/alkalis and most solvents, Quick Curing (forms a skin in 10-30 minuets depending on temperature) Resistant to temperature extremes ‐40°C to +150°CAvailable in black, brown, crystal clear, grey and white.CT1 – £10.50 inc shp – Adhesive SealantA favourite amongst boating enthusiasts CT1 is suitable as a universal adhesive and will work in all applications. CT1 has no shrinkage and can be applied in both damp and wet conditions. It adheres to most metals (including lead) as well as glass, mirrors, wood, polystyrene and GRP.Tensile Strength -1.72 MPa.Elongation Break – 350%Resistant to seawater, aliphatic solvents, oils , greases and diluted organic acids.Available in clear, white, black, grey, beige, brown, oak, blue and silver.3M 5200 – £24 inc shp – Adhesive Sealant3M 5200 is a one part polyurethane adhesive sealant which reacts chemically with water to deliver an extremely strong mechanical bond. Multiple sources including boat yard workers have claimed it’s so strong its use as a marine sealant should be limited. It is apparently too strong for bedding equipment that may need replacing or maintaining in the future. However, It claims it is ideal for seals and joints both above and below the waterline. Debond by Marine Formula can be used to remove the sealant but be warned, it’s expensive stuff!Tensile Strength -1.72 MPa.Elongation Break – 874%Great flexibility once set.Resistant vibration, swelling or shrinking.Available in white.Sabatack 720 – £13 inc shp – Adhesive SealantSabatack 720 is a one component MS polymer-based adhesive sealant ideal for use in the marine environment. It’s primary meant to be used for sealing, seams overlaps and joints with bonding being its secondary function.Tensile Strength -2.2 MPa.Elongation Break – 300%Fast curing.Resistant to UV.Resistant to high temperatures.Avaialble in white, grey and black.HOW TO TELL WHEN ITS TIME FOR RE-BEDDING.Once you own a boat you are trapped in an eternal circle of labour, and whether it’s for leisure, living or work purposes you will always need to maintain it. You can limit your workload by using the right method with the right gear. Sealing and re-bedding deck equipment most definitely fall’s into the laborious circle but with the right adhesive or sealant and a bit of skill, you can seal your deck with no problems.Your boat for obvious reasons needs to be tighter than a duck’s arse; most importantly below the waterline, but don’t disregard your topside leaks. They have the potential given adequate time and rainfall to sink a boat.Things to look out for –Dirt trails – your sealant has failed and is now allowing dirt to collect under your deck equipment. If it’s not rust or corrosion then it may be that failing sealant is the cause. If your outer layer has perished then there is a chance that your seal will break next, so it’s time to take action.Water – visibly dripping through into your cabin during rainy days. Leaking water can often be seen forming small droplets on the bottom of protruding bolt heads. Wait for a forecast of rain or cheat and use a hose to find leaks. If you get your bilge bone dry beforehand, you’ll be able to follow the trails of water from any leaky hardware by looking at your bilge areas with a hand torch. This method works amazingly well. If you have a dirty bilge it seems to be even easier and the trail seems to show up clearer where the dirt is wet.Choose The Right SealantLots of questions will need to be answered before wasting your money on the wrong kind of marine sealant. Each sealant bonds and reacts with materials in a multitude of ways. Some sealants, for example, will crack perspex boat windows if they are not made from an acrylic compatible chemical. There is nothing more frustrating than bolting and re-bedding all of your boat’s windows, only for someone to come along at the end and tell you that you’ve used the wrong sealant – Doh!Sealants were originally designed to patch holes in planes during the war but since then they’ve got a lot more complicated. Corporate competition means companies are continuously trying to outdo each other. The marine industry is constantly screaming out for products that last longer and perform better and subsequently, we are fed increasingly better sealants. A lot of companies who create sealants eventually wise up to the fact that their product will work in the ‘marine’ industry, and often subtly add it to their datasheet without it being a specific marine product and liable for leisure tax.Don’t worry breaking your requirements into some simple steps really helps.Strength – how strong is the mechanical bond strength (some manufacturers give this information)?Flexibility – can the sealant move without breaking apart and can it absorb impact?Compatibility – will it work with your material you wish to bond it too? Will it be safe for below the waterline?Serviceability – how easily will I be able to remove and replace the sealant, how long does it take to set?Service life – how long does the manufacturer claim their product lasts and is it UV resistant?We’ve even created a beautiful acronym for you to remember: ‘SFCSS’ (pronounced; Suu-Fuu-Cissss). See, if that’s not catchy enough for you then I don’t know what is!Terms ExplainedTensile Strength – the resistance of a material to breaking under tension. To put it even clearer this is the amount of force a material can take until it breaks apart. This is measured in N/mm2 to MPa and can normally be found on a product datasheet.Elongation Break – Is the % of stretching that the product breaks at. Some sealants have been designed to stretch more than others.So to summarise, imagine you’re an evil man wanting to pull someones’ arms off using horses. Tensile strength is the amount of horse’s you would need to pull them off which is measured in N/mm2 or MPa. The elongation break is how long the poor persons’ arms will stretch before they rip off – ouch!”

Thanks for A2A.Nanotechnology is a subject which requires attention to details.Nanotechnology deals with understanding, controlling and manipulating matter at the level of individual atoms and molecules in the range of 0.1–100 nm (10-9 m). It creates materials, devices, and systems with new properties and functions. The role of nanotechnology in the conceiving of innovative infrastructure systems has the potential to revolutionize the civil engineering practice and widen the vision of civil engineering.Some of its applications are examined in detail below:A. CONCRETEConcrete is one of the most common and widely used construction materials. Nanotechnology is widely used in studying its properties like hydration reaction, alkali silicate reaction (ASR) and fly ash reactivity [2]. Alkali silicate reaction is caused due to alkali content of cement and silica present in reactive aggregates like chert. The use of pozzolona in the concrete mix as a partial cement replacement can reduce the likelihood of ASR occurring as they reduce the alkalinity of a pore fluid. Fly ash not only improves concrete durability, strength and, importantly for sustainability, reduces the requirement for cement, however, the curing process of such concrete is slowed down due to the addition of fly ash and early stage strength is also low in comparison to normal concrete.Addition of Nano-silica leads to the densifying of the micro and nano structure resulting in improved mechanical properties. With the addition of nano-SiOpart of the cement is replaced but the density and strength of the fly-ash concrete improves particularly in the early stages. For concrete containing large volume fly ash, at early age it can improve pore size distribution by filling the pores between large fly ash and cement particles at Nano scale. The dispersion/slurry of amorphous nano-SiOis used to improve segregation resistance for self-compacting concrete [26]. The addition of small amount of carbon nanotube (1%) by weight could increase both compressive and flexural strength [1]. This can also improve the mechanical properties of samples consisting of the main portland cement phase and water. Oxidized multi-walled nanotubes (MWNT’s) show the best improvements both in compressive strength (+ 25 N/mm) and flexural strength (+8 N/mm) compared to the reference samples without the reinforcement.Cracking is a major concern for many structures. University of Illinois Urbana-Champaign is working on healing polymers, which include a microencapsulated healing agent and a catalytic chemical trigger [19]. When the microcapsules are broken by a crack, the healing agent is released into the crack and contact with the catalyst. The polymerization happens and bond the crack faces. The self-healing polymer could be especially applicable to fix the micro cracking in bridge piers and columns. But it requires costly epoxy injection. Research has shown that an anaerobic (one that does not require oxygen) microorganism incorporated into concrete mixing water results in a 25% increase in 28-day strength. The Shewanella microorganism was used at a concentration of 105 cells/ml and nanoscale observation revealed that there was a deposition of sand-cement matrix on its surface. This led to the growth of filler material within the pores of the cement sand matrix and resulted in increased strength.Finally, fibre wrapping of concrete is quite common today for increasing the strength of pre-existing concrete structural elements. An advancement in the procedure involves the use of a fibre sheet (matrix) containing nano-silica particles and hardeners. These nanoparticles penetrate and close small cracks on the concrete surface and, in strengthening applications, the matrices form a strong bond between the surface of the concrete and the fibre reinforcement.It is evident from the Fig.1 that the SCCNFC (self consolidating concrete Nano fibre concrete) column failed at higher loads and with larger deflection than the SCRC (steel confined reinforced concrete) column. Additionally, the SCCNFC column was much stiffer than the SCRC column and exhibited higher energy dissipation. SCCNFC can also be used as a type of self- Structural Health Monitoring system.B. STRUCTURAL COMPOSITESSteel is a major construction material. FHWA together with American Iron and Steel Institute and the U.S. Navy developed new, low carbon, high-performance steel (HPS) for bridges in 1992 with higher corrosion-resistance and weld ability by incorporating copper nanoparticles from at the steel grain boundaries [16].Sandvik NanoflexTM is new stainless steel developed by Sandvik Nanoflex Materials Technology. Due to its high performance, it is suitable for application which requires lightweight and rigid designs. Its good corrosion, formability and wear resistance can keep life-cycle costs low [22] MMFX2 is nanostructure-modified steel, produced by MFX Steel Corp, USA. Compared with the conventional steel, it has a fundamentally different microstructure- laminated lath structure resembling “plywood” as shown in Fig.2. Due to the modified nanostructure, MMFX steel has superior mechanical properties, e.g. higher strength, ductility and fatigue resistance, over other high-strength steels. These material properties can lead to longer service life in corrosive environments and lower construction costs. The MMFX2 steel has similar corrosion resistance to that of stainless steel, but at a much lower cost. So far, the MMFX steel has gained certification for use in general construction throughout the US.Carbon nanotubes are over 100 times stronger than steel and only one-sixth of the weight in addition to its high thermal and electrical conductivities. A CNT composite has recently been reported to be six times stronger than conventional carbon fibre composites [13]. Additionally, unlike carbon fibres which fracture easily under compression, the nanotubes are much more flexible and can be compressed without fracturing. CNT composite reinforced structures have a 50- to 150-fold increase in tensile strength, compared with conventional steel-reinforced structures.C. COATINGSThe coatings incorporating certain Nano particles or Nano layers have been developed for certain purpose including: protective or anti-corrosion coatings for components; self-cleaning, thermal control, energy saving, anti-reflection coatings for glass/windows; easy-to-clean, antibacterial coatings for work surfaces; and more durable paints and anti-graffiti coating for buildings and structures. For example: Self-cleaning windows have been developed and marketed by Pilkington, St. Gobain Co., and others [9]. This coating works in two stages. First, using a ‘photocatalytic’ process, nanosized TiOparticles in the coating react with ultra-violet rays from natural daylight to break down and disintegrate organic dirt. Secondly, the surface coating is hydrophilic, which lets rainwater spread evenly over the surface and ‘sheet’ down the glass to wash the loosened dirt away. It can therefore reduce airborne pollutants when applied to outdoor surfaces. Coating of 7000 mof road surface with such a material in Milan in 2002 has led to a 60% reduction in nitrogen oxides concentration at street level [22]. Research has also demonstrated that bimetallic Nano particles, such as Fe/Pd, Fe/Ag, or Zn/Pd, can serve as potent reductants and catalysts for a large variety of environmental contaminants [11].Another approach to create self-cleaning surface coating has been the development of ‘Lotus Spray’ products by BASF [12], based on ideas of replicating the spotless lotus leaves. The product offers 20 times more water-repellent property than a smooth, wax coating. With its applications in the construction industry, the company aims to develop a product that will retain its lotus effect even after an abrasion with sandpaper.Special coatings can also make the applied surface both hydrophobic and oleophobic at the same time. These could be used for anti-graffiti surfaces, carpets and protective clothing etc. Researchers in Mexico has successfully developed a new type of anti-graffiti paint DELETUM, by functionalising nanoparticles and polymers to form a coating repellent to water and oil at the same time, as shown in Fig. 3.As a result, the coated surface is non-stick or very easy to clean, and able to withstand repeated graffiti attacks. Furthermore nanostructured coatings can be used to selectively reflect and transmit light in different wavebands [4]. Research is focusing on smart and responsive materials able to sense and adapt to surroundings and change their appearance, such as whose colour changes as a function of temperature, and cladding which responds to heat and light to minimise energy use in buildings [16].D. GLASSFire-protective glass is another application of nanotechnology. This is achieved by using a clear intumescent layer sandwiched between glass panels (an interlayer) formed of fumed silica (SiO) nanoparticles which turns into a rigid and opaque fire shield when heated. The electrochromic coatings are being developed that react to changes in applied voltage by using a tungsten oxide layer; thereby becoming more opaque at the touch of a button. Because of the hydrophobic properties of TiO, it can be applied in antifogging coatings or in self-cleaning windows [1]. Nano-TiOcoatings can also be applied to building exteriors to prevent sticking of pollutants, and thus reduce a facility’smaintenance costs [15].E. NANOSENSORSNanotechnology enabled sensors/devices also offer great potential for developing smart materials and structures which have ‘self-sensing’ and ‘self-actuating’ capability. The device used for air bags in cars is such an example. Nano and Micro electrical mechanical systems (NEMS & MEMS) sensors havebeen developed and used in construction to monitor and/or control the environment conditions (e.g. temperature, moisture, smoke, noise, etc.) and the materials/structure performance (e.g. stress, strain, vibration, cracking, corrosion, etc.) during the structure’s life. Nano sensor ranges from 10m to 10m which could be embedded into the structure during the construction process.Cyrano Sciences has developed electronic noses based on an array of different polymer nanometre-thin film sensors [30]. Siemens and Yorkshire Water are developing autonomous, disposable chips with built-in chemical sensors to monitor water quality and send pollution alerts by radio [26]. Smart aggregate, a low cost piezoceramic-based multi-functional device, has been applied to monitor early age concrete properties such as moisture, temperature, relative humidity and early age strength development [30]. Also it can provide an early indication before a failure of the structure occurs.F. BULK INSULATING MATERIALSNanoPore has developed bulk nanoporous silica compounds with embedded organic molecules which perform up to 10 times better than conventional insulating materials [11, 32]. The superior insulation characteristics of these low density, highly porous solids are due to the unique shape and small size (10-100 nm) of its large number of pores. So far, these new insulating compounds have been used in applications that require excellent thermal performance, optimum energy efficiency, or minimum insulation thickness.G. PLASTICSThe carbon fibre reinforced plastics (CFRP) being light weight material does not exhibit good electrical properties. CNTs are among the stiffest and strongest fibers known, and have high electrical conductivity. At IFAM in Bremen, researchers employed plasma technology in order to transfer their properties to CFRPs since these micro- or nanoparticles must be highly homogeneous, and sometimes very closely bound to the polymer. Dr. Jörg Ihde, explains: “We spray the particles i.e. the nanotubes into this atmospheric plasma.” They immediately fall into the selected solvent, which can then be used to further process the polymer. The whole procedure takes just a few seconds”. This can be pressed onto an electronic component so heat is dissipated directly.H. PLASTIC SOLAR CELLThe most promising application in the areas of energy and environment leading to the sustainable building is the development of fuel cells and photovoltaic. In the last few years, considerable efforts have been made to develop plastic solar cells in Fig. 4, much simpler and cheaper to produce than that of conventional silicon semiconductor solar cells. Replacing conventional lamps with LEDs in the United States alone could generate energy savings of up to $100 billion by 2025 and reduce carbon emissions by 200 million tons per year [17].I. BITUMENThe bentonite (BT) and organically modified bentonite (OBT) were used to reinforce and modify asphalt binder by melt processing under sonication and shearing stresses. The BT modified asphalt possess intercalated structure while OBT modified asphalt possessed exfoliated structure. The BT and OBT modified asphalts have shown greater softening point, viscosity, higher complex modulus, lower phase angle and higher rutting parameter and better rheological properties than the base asphalt. But the ductility of the modified asphalts decreased with the addition of BT and OBT. They have significantly lower creep stiffness. Therefore, the low temperature cracking resistance was improved by addition ofBT and OBT. The OBT modified asphalts has better properties than the BT modified asphalts.J. BIOMIMETIC MATERIALSBiomimetics is the science of mimicking nature, and biomimetic materials seek to replicate the best features of natural materials. Examples such as honeycomb giving a lightweight structure with exceptional mechanical strength, antler bone being tougher than any man-made ceramic composites, lotus leaf giving self-cleaning surfaces, hameleon’s skin changing colours with the environment, etc. By manipulating materials at the atomic level enabled by nanotechnology advances, biomimetic materials research provides a productive approach of new materials and molecular manufacturing.K. SMART MATERIALSSmart materials are materials with properties engineered to change in a controlled manner under the influence of external stimuli like temperature, force, moisture, electric charge, magnetic fields and pH. Examples are Piezoelectrics, Thermoresponsives, Shape Memory Alloys (SMA), Polychromic, Chromogenic materials etc. Like piezoelectrics that alter their shape under the influence of the electric field, SMA change shape due to magnetic fields. Intelligent Reinforced Concrete Structure (IRCS) is conceptualised on them. The IRCS has multiple functions which include self-rehabilitation, self-vibration damping, and self-structural health monitoring. In this a special type of piezoceramic called PZT (lead zirconate titanate), which possesses a strong piezoelectricity effect, and a special type of SMA called Nitinol, which has good corrosion resistance and large actuation stress, will be used. The proposed concrete structure is reinforced by martensite Nitinol cables using the method of post-tensioning. The martensite Nitinol significantly increases the concrete’s damping property and its ability to handle large impact. In presence of cracks due to explosions or earthquakes, by electrically heating the SMA cables, the SMA cables contract and close up the cracks.To detect possible cracks inside the concrete structure, a PZT patch is used as an actuator to generate waves and other distributed PZT patches are used as sensors to record the received vibration signals.L. NANOTECHNOLOGY IN FIRE PROTECTIONFire resistance of steel structures is often provided by a coating of spray on cementitious process which is no more popular because they need to be thick, tend to be brittle and polymer additions are needed to improve adhesion. However, research into nano-cement (made of nano-sized particles) has the potential to create a new paradigm in this area of application. This is achieved by the mixing of carbon nanotubes (CNT’s) with the cementious material to fabricate fibre composites that can inherit some of the outstanding properties of the nanotubes such as strength. Polypropylene fibres are also being considered as a method of increasing fire resistance and this is a cheaper option than conventional insulation. CNTs can also be used to produce protective clothing materials because of their flame retardant property.III. IMPACTS OF NANOTECHNOLOGY ON CONSTRUCTIONA. MERITS1) Compared with conventional TiO, TiOat the nano-scale experiences a 500% increase in surface area and a 400% decrease in opacity. Current nano-TiOproduction levels have reached approximately 4 million metric tons at a price of approximately $45/kg to $50/kg vs. $2.5/kg for conventional TiO.2) The CNT market worldwide is expected to grow from $51 million in 2006 to more than $800 million by 2011 (BCC Research 2008).3) Nano-modified concrete cuts down construction schedules while reducing labour-intensive (and expensive) tasks. Also it can reduce the cost of repair and maintenance.4) The paint and coatings industry consists of approximately annual sales of $20 billion (Baer et al. 2003). Nano-alumina and titania have a four- to six-fold increase in wear resistance, with doubled toughness and bond strength (Gell 2002).5) The potential global market of nanocomposites is estimated at $340 billion for the next two decades (Roco and Bainbridge 2001).6) The market for fire protection systems totalled approximately $45 billion in 2004 and is expected to grow to more than $80 billion by 2010 (Helmut Kaiser Consultancy 2008)7) Self-repairing asphalt, healing and rejuvenating nanoagents for asphalt (Partl et al. 2006), and self-assembling polymers improve asphalt mix.8) Nano sensors embedded in infrastructural materials can provide, at minimum cost, fully integrated and self-powered failure prediction and forecasting mechanisms for high-capital structures (e.g., reservoirs, nuclear power plants, and bridges).B. DEMERITS1) Because of their small particle size, nano particles have the potential to negatively affect the respiratory and digestive tracks and the skin or eye surface [4] thus exposes workers to hazards.2) Since nanotechnology-related industries are relatively new, the type of worker who is employed in construction research and development (or even some field applications) must have an interdisciplinary background.3) New policies in the context of nanotechnology will require cooperation between various levels of government, R&D agencies, manufacturers, and other industries.4) Small production volumes and high cost remain the main barriers to the use of nanotechnology (The Royal Society 2004)5) The time for commercializing a product is long. E.g. the concrete, which can eliminate the need for reinforcing bars, is projected to be commercialized by approximately 2020.IV. SUSTAINABLE CONSTRUCTIONAt an annual production rate of 2.35 billion tons, the cement industry contributes about 5% to global anthropogenic COemissions. Additives such as belite, calcium sulfo-aluminate and calcium alumino-ferrite (BASF 2008) have been found to reduce the COemissions by nearly 25% in the production phaseA wall made of nano-modified concrete during a cold weather season could potentially be used as a thermal insulator when the outside temperature falls or used as a conductor when the ambient temperature inside the building is low, thereby reducing the energy load required for conditioning the building interior.With further development of LED & OLED technology and progress in the insulating materials and smart glazing, the vision for buildings to meet their own energy requirement will become a reality.V. FUTURE PROJECTION OF NANOTECHNOLOGY IN CONSTRUCTIONThere is substantial money flowing into nano-related research from multinational corporations and venture capital investments [4, 16]. Many of the world’s largest companies such as IBM, Intel, Motorola, Lucent, Boeing, Hitachi, etc. have all had significant Nano-related research projects goingon, or launched their own nanotech initiatives. By 2015, the National Science Foundation estimates that nanotechnology will have a $1 trillion effect on the global economy. To achieve this market-sized prediction, industries will employ nearly two million workers towards advancements in many Nano materials, Nano structures, and Nano systems. The time needed for commercializing a product is long because industries may prefer monitoring development in research agencies and laboratories before making substantial investments. Furthermore, nanotechnology development, particularly in conjunction with biomimetic research will lead to truly revolutionary approaches to design and production of materials and structures with much improved efficiency, sustainability and adaptability to changing environment.Source : Nanotechnology in Civil EngineeringOTHER WEBSITES :APPLICATION OF NANOTECHNOLOGY IN CIVIL ENGINEERINGNanotechnology In Civil EngineeringNANOTECHNOLOGY IN CIVIL ENGINEERING - SANTHOSH BALAJI