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THAILAND –

DEVELOPMENT AND APPLICATION OF CEMENTITIOUSCOMPOSITES

Dr. Naveed AnwarAsian Center for Engineering Computations and Software (ACECOMS)Asian Institute of Technology (AIT), BangkokTHAILAND

Dr. Pichai NimityongskulSchool of Engineering and TechnologyAsian Institute of Technology (AIT), BangkokTHAILAND

Dr. Lilia Robles AustriacoCollege of Engineering, Angeles University, Angeles CityPHILIPPINES

CBM-CI International Workshop, Karachi, Pakistan Dr. Naveed et. al

ABSTRACT: Like many other countries in the world, significant developments in cementitiousmaterials have been made in Thailand, spearheaded by the International FerrocementInformation Center (IFIS) located at Asian Institute of Technology (AIT) Thailand, severalother academic institutions, and the construction industry. This paper highlights some ofthese developments together with their applications. Special focus is given to ferrocementand laminated cementitious composites, and the use of indigenous materials such as vetivergrass, thai silk, bamboo, etc. Different aspects such as materials, design, and constructionare discussed together with the application of finite element analysis to structures madefrom cementitious composites.

1. INTRODUCTION

Composite materials are engineering materials made from two or more constituent materialsthat remain separate and distinct on a macroscopic level while forming a single component.Composites represent a major development of the twentieth century in materials scienceand engineering. These unique man-made materials are quite different from conventionalconstruction materials such as steel, wood, and aluminum. They consist of two main

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constituents: a structural constituent, such as fibers, particles, laminate or layers, flakes,and fillers, and the body constituent or matrix, which acts as a binder, stabilizer and loaddistributor, encloses the composite, and gives it its bulk form.

A major advantage of composites is that they are corrosion-resistant, which results in a lowlife-cycle cost for the structures in which they are used. Composites are often lightweight,which results in economical transportation, easier handling, and faster erection usingrelatively light equipment, and often without any special equipment. This translates intosavings in labor costs. Faster construction also means minimum disruption to businessesand traffic, a big advantage. The composites often utilize local materials and constructiontechniques, thus making them suitable for low cost and environmentally friendly construction.The most primitive composite materials were straw and mud in the form of bricks forbuilding construction. The most advanced examples perform routinely on spacecraft indemanding environments. The most visible applications pave the roadways in the form ofeither steel and aggregate reinforced Portland cement or asphalt concrete. Those compositesclosest to personal hygiene are used in the shower stalls and bathtubs made of fiberglass.Solid surface, imitation granite and cultured marble sinks and countertops are widely usedto enhance our living experiences [1].

2. CEMENTITIOUS COMPOSITES IN THAILAND

2.1 Ferrocement

Ferrocement is a well-known composite made from cement paste and closely spaced meshreinforcement. Considerable research and development has been done on this compositeworldwide, with a major coordination and promotional effort by the International FerrocementInformation Center located in Thailand.

2.1.1 International Ferrocement Information Center

The International Ferrocement Information Center (IFIC) was founded in October 1976 atthe Asian Institute of Technology under the joint sponsorship of the Institute's StructuralEngineering and Construction Program and the Library and Regional Documentation Center(LRDC). IFIC was established because of the recommendations made in 1972 by the U.S.National Academy of Science's Advisory Committee in Technological Innovation (ACTI).

The objectives of IFIC are to collect, repackage and disseminate information related toferrocement and related materials and to promote the utilization of ferrocement materials.As per demand IFIC has also expanded its coverage to other low-cost construction materialsincluding rice husk ash cement, fiber reinforced cement and other laminated cementitiousmaterials. IFIC has also established Ferrocement Park in AIT, where sample ferrocement


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products are kept for display. IFIC was formerly headed by the third author of this paperfor several years and is currently headed by the second author.

2.1.2 Application of Ferrocement in Thailand

Ferrocement has been used for various purposes in Thailand, including marine applications,agricultural applications, water and sanitation applications, industrial applications, ruralenergy applications, housing applications, etc.

Prefabricated ferrocement panels are used in the design and construction of traditional Thaihouses. The replacement of wood by prefabricated ferrocement panels significantly reducedthe construction costs of traditional houses [2].

Research headed by the first and the second authors was carried out on the design, analysis,construction, and testing of ferrocement water tanks for refugee camps by the Asian Centerfor Engineering Computations and Software (ACECOMS) and IFIC for the United NationsHigh Commissioner for Refugees (UNHCR). A training video on the construction sequencewas also prepared to train the local unskilled labor for the construction of this tank at remotelocations. The designed capacities of tanks were 45,000, 75,000, and 90,000 liters [3].

A ferrocement ellipse-shaped house has been designed and constructed by Intact StructureInc., USA [4]. The first author of this paper engineered the design. The structure has beenanalyzed for hurricane level wind forces as well as very high intensity earthquakes to enableits construction as regular houses as well as shelters in adverse environmental forces. Thisferrocement house has already been constructed in Mexico, and construction is planned forThailand, the Philippines, and Pakistan. Full finite element shell models were generated forboth the UNHCR water tank and the Intact House structure using the appropriate propertiesfor ferrocement material.

Ferrocement has been used in the construction of grain storage bins in Thailand to reducelosses from attacks by birds, insects, rodents, and moulds. Thailo, a conical ferrocementbin, was designed and first constructed at the Asian Institute of Technology (AIT), Bangkok,Thailand [5]. Storage capacities range from one to ten tons (1000 kg to 10,000kg). Thisbin has proved to be structurally sound, and the construction has provided adequate toprotect the product against rodent, insect and bird attacks.

Similarly, biogas digesters and biogas holders constructed with ferrocement lead to aconsiderable cost reduction. Ferrocement has also been used as digester lining when bricksare not economically available. Ferrocement septic tanks and ferrocement toilet bowls havealso been used in Thailand. Ferrocement and bamboo-cement rainwater collection tanksare being built on a self-help basis by villagers under the supervision of an appropriatetechnology group to provide clean drinking water.


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More than 30 ferrocement boats have been built with sizes varying between 5-24m; theseare used for recreational, fishing and transportation purposes [6].

Ferrocement manhole covers have been used to replace conventional cast iron manholecovers. The ferrocement manhole covers are cheaper, lighter and have improved performancecompared to traditional cast iron manhole covers [7]. The hybrid ferrocement manholecover’s price is about one-third of the cast-iron covers currently used, and the weight isapproximately 40% less.

Joint research is being conducted by the Royal Thai Air Force Academy, Thailand, and theAsian Institute of Technology (AIT) on the blast load resistance of ferrocement panels. Theresults show that even ferrocement panels of thickness 2.0 cm possess higher blast loadresistance capabilities than 10-cm thick conventional plastered masonry walls made ofbricks and blocks [8]. Similarly, research has also been conducted on the use of ferrocementas a strengthening and retrofitting material to withstand extreme heat or fire [9]. Jacketedferrocement with other structural components like reinforced concrete (RC), prestressedconcrete (PC) or steel enhanced the fire resistance of the composite element.

2.2 Vetiver Grass

A research team from the School of Engineering and Technology (SET) at AIT, led by thesecond author of this paper, has recently presented patent certificates on vetiver grassdevelopment technology to His Majesty King Bhumibol Adulyadej of Thailand. The patentspresented to the King were vetiver grass cement composites, the use of vetiver grass ashas a cement replacement, the process of producing vetiver grass ash, and construction of asilo from vetiver grass and clay.

2.2.1 Vetiver-Clay Silo

Figure 2.1 shows an application of vetiver grass and clay for a low-cost paddy storage silo. This resulted from research conducted on vetiver grass (that uses vetiver grass and clay).Vetiver grass is used to reinforce clay slurry or adobe in a vetiver-clay composite. Thevetiver grass serves as the reinforced fiber and clay as the matrix.

This technology has created low cost construction materials that can save energy, minimizepollution, and be produced by villagers themselves. The research team used vetiver grassto replace cement for construction, together with a locally available material as the bondingagent in producing the vetiver grass sheet. The ash gives the concrete a unique property,increasing the concrete resistance against acidic attack.


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Figure 2.1 Layer of the pilot silo wall using vetiver grass clay bundle.

2.2.2 Prefabricated Vetiver-Clay Composite for Housing Applications

The research teams headed by the second author are also working on a project called“Development of Prefabricated Vetiver-Clay Composite for Housing Applications” forconstructing a low-cost house for farmers. Research is also been carried out on the utilizationof vetiver grass as a material for constructing refugee camps. The purpose of this researchis to construct a prefabricated system so that knockdown materials can be produced firstand can later be constructed as houses within a one week.

Further research work is being carried out on the use of vetiver grass ash for engineeringwork, vetiver grass sheet for interior design, and vetiver grass as a replacement for packagingfoam.

2.3 Bamboo Reinforced Concrete

In Thailand, bamboo is mostly concentrated in an area of about 850,000 hectares located130 km west of Bangkok. The total weight of bamboo grown in this area is over 7 millionair-dried tons, out of which 1.65 million tons grow in an economically accessible area [10].These bamboo plants have been used for various purposes including civil engineeringstructures.

In Thailand, bamboo reinforced concrete roads have received special attention. In 1989,the Public Works Department of Thailand started a program to construct bamboo reinforcedconcrete pavement village roads. Altogether, 863 village road projects [11], with a totallength of more than 500 km spreading all over the country, have been constructed so far.


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Bamboo reinforced concrete is also used for the construction of water tanks. In Thailand,it is estimated that more than 50,000 bamboo reinforced concrete water tanks have beenbuilt, and the investment has been over 300 million baht (US $ 11.5 million) [12].

2.4 Glass Fiber Reinforced Concrete (GRC)

GRC is a unique mixture of cement and sand reinforced with a special glass fiber, creatinga thin but strong material that may be easily formed into a wide variety of ornamentalshapes. Many of Bangkok's most recognized buildings, including the Wall Street Tower,Peninsular Plaza, Amarin Plaza and the New Grand Hyatt Erawan Hotel, use glass fiberreinforced concrete (GRC) for decorative and architectural emphasis [13]. Other glassfiber reinforced applications include bathtubs, shower units, patio covers, exterior buildingpanels, and even door panels.

2.5 Other Fiber Reinforced Concrete

A study on the use of Thai silk as reinforcement in fiber-reinforced composites was carriedout at AIT [14]. The objective of the research was to find a fiber that can be used to replacecertain non-renewable synthetic fibers, such as substituting glass with renewable naturalfibers as reinforcement in polymer composites. The study result showed that the using thesame fiber volume fraction, the Thai silk fiber reinforced matrix cost 33 % less than theglass fiber reinforced matrix.

3. SUPPLEMTARY CEMENTITIOUS MATERIALS

The use of active or inactive micro-fillers such as silica fume, fly ash, and metakaolin hasa significant effect on the matrix, porosity, strength, and durability [15]. There has been alot research work carried out on such cementitious materials in Thailand. The most widelyused cementitious material is fly ash from industrial waste. Out of all of the cementitiouscomposites that are used to replace cement, the percentage of fly ash is about 90%, whereasrice husk ash is 8%, and remaining materials are about is 2%.

3.1 Fly Ash

The amount of fly ash produced annually in Thailand has been approximately 3 milliontons during the past 10 years. About 95% of the total production is obtained from the MaeMoh power generating plant operated by the Electricity Generating Authority of Thailandin Lampang province, in the north of Thailand [16]. This fly ash contains a high percentageof calcium and is used quite extensively for construction in Thailand. Significant researchhas been conducted as a part of master and doctoral thesis work at the School of Engineeringand Technology (SET), AIT, on the mix design of fly ash cement concrete using Mae MohAsh.


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An original research group consisting of researchers from seven universities in Thailandwas formed to study the properties of fly ash and concrete using fly ash. This group publishedmore than 30 research reports and more than 100 technical papers before the year 2000.After this initial effort, investigators at many other universities also started to conductresearch on fly ash, and several publications have been produced since then.

Fly ash has become an even more popular cement replacing materials for concrete applicationsince 1997, when the country faced an economic crisis. One of the main reasons, of course,is that the cost of fly ash is much lower than that of cement. Fly ash has already become aconventional cement replacing material in Thailand [16], so that the majority of ready-mixed concrete plants, including those in precast concrete and on-site ready mixed plants,are using it as a major cementitious material. For ready-mixed concrete, fly ash is normallyused to replace cement in the range of 20 to 30% by weight.

For the precast concrete and concrete product industries, fly ash is normally used in worksthat do not require early strength, such as non-prestressed concrete works. In prestressedconcrete industries, fly ash is also used, but with a maximum cements replacement of onlyup to 10% [16]. The exception may be in the case of self-compacting concrete applications,in which fly ash may be used up to a range of 30% to 50%.

Some cement companies have made efforts to introduce ready-blended fly ash cement intothe concrete market in Thailand [16]. Most of these are introduced as cements for durabilitypurposes, such as cement for marine environments that have a high resistance against sulfateattack and chloride-induced steel corrosion, sulfate-resisting cement, low-heat cement, etc. Fly ash is also used in enhancing the performance and reducing the cost of some repairmaterials used in grouting work. Fly ash has also been studied as a stabilizer and to controlthe expansion of expansive cement

3.2 Rice Husk Ash

In Thailand, large amounts of agricultural products are produced, including large amountsof rice, coconut, sugarcane, jute, etc. [17]. It is also well known that Thailand and otherAsian countries produce a large amount of paddy [18]. Rice husk, a by-product of ricepaddy, is used as a fuel in boilers in the rice mills or small electricity generating plants andfor brick burning. Although the increased use of rice husk is evident, much of the husk isdisposed of by open field burning. There is worldwide interest in making cement from ricehusk because when burnt it contains a very high percentage of silica (SiO2), which is oneof the main constituents in ordinary portland cement.


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3.3 Other Agricultural Wastes

More than four years ago, the Building Scientific Research Center (BSRC) conductedresearch on the use of natural fibers as an admixture in composite materials. A newlightweight composite concrete [19] and particleboards [20] were developed using youngcoconut (Cocos nucifera), durian peel (Durio zibethinus) and coconut coir. The manufacturedspecimens have good thermo physical properties, especially low thermal conductivity.Nowadays, there are some on-going studies on the durability and long-term performanceof these materials so that commercial development might start [21].

4. CONCLUSIONS

This paper presented the development and applications of cementitious composites inThailand. It can be said that Thailand has become a very successful country regarding theuse of cementitious composites in the construction industry. The use of laminated compositessuch as ferrocement and other cementitious materials, especially fly ash, have become asignificant factor in conventional and innovative construction applications. Use of indigenousmaterials such as bamboo and vetiver grass is also finding their way into cementitiouscomposite research and applications.

REFERENCES

[1] http://en.wikipedia.org/wiki/composite-material[2] W. Kongsith, Design and Construction of Traditional Thai House using Ferrocement, AIT

Thesis no ST-91-14, Asian Institute of Technology, Bangkok, Thailand, 1991.[3] ACECOMS, IFIC, UNHCR, Research on Large Ferrocement Water Tanks-Design, Construction

and Prototype Testing, ACECOMS, AIT, Thailand, Jan 2002.[4] ACECOMS, Intact Structure Inc., Structural Design of Ferrocement Housing, ACECOMS,

AIT, Thailand, March 2007.[5] AIT, IFIC, Lecture notes: Short Courses on Design and Construction of Ferrocement Structures,

Asian Institute of Technology, Bangkok, Thailand, 8-12 Jan 1985.[6] B. K. Paul and R. P. Pama, Ferrocement. International Ferrocement Information Center, Asian

Institute of Technology, Bangkok, Thailand, 1978.[7] N. Lin, P. Nimityongskul, C. Kasatewit and S. Sayamipuk, Fatigue Strength of hybrid

ferrocement manhole covers. Proceedings of the Eighth International Symposium and Workshopon Ferrocement and Thin Reinforced Cement Composites, 6-8 February 2006, Bangkok,Thailand, pp. 229-240.

[8] T. Pheeraphan, P. Joyklad and P. Nimityongskul, Experimental study on blast load resistanceof ferrocement panels. Proceedings of the Eighth International Symposium and Workshop onFerrocement and Thin Reinforced Cement Composites, 6-8 February 2006, Bangkok, Thailand,pp. 335-364.


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[9] V. Greepala, P. Nimityongskul, Structural integrity and insulation property of ferrocementexposed to fire. Proceedings of the Eighth International Symposium and Workshop onFerrocement and Thin Reinforced Cement Composites, 6-8 February 2006, Bangkok, Thailand,pp. 399-412.

[10] B. Pakotiprapha, A Study of Bamboo Pulp and Fiber Cement Paste Composites, AIT Diss.No. D20, Asian Institute of Technology, Thailand, 1976

[11] Bangkok, International Labour Office, Planning and Implementing Local Infrastructure Works-Guidelines for Tambon Administrative in Thailand, 2004.

[12] C. Vadhanavikkit, and Y. Pannachet, Investigations of Bamboo, Reinforced Concrete WaterTanks, 3rd International Rainwater Cistern Systems Conference Khon Kaen, Thailand, January,1987.

[13] http://www.gel.co.th/product/glassfiber-reinforced-concrete.html[14] N. Tinnam, A Feasibility Study for the use of Thai Silk as Fiber Reinforcement in Polymer-

Based Matrix, AIT Thesis no ST-03-13, Asian Institute of Technology, Bangkok, Thailand,2003.

[15] Naaman A. E, Ferrocement and Laminated Cementitious Composites. Techno Press 3000,Michigan, USA, 2000.

[16] S. Tangtermsirikul, Development of fly ash usage in Thailand. The International Workshopon Project Management, Kochi, Japan, March, 2005.

[17] Thailand Office of Agriculture Economic. Agriculture statistics of Thailand crop year [Online]:[18] T. Chareerat , V. Detphan and P. Chindaprasirt, Initial study on rice husk ash and fly ash-

based flowable geopolymer mortar. Proceeding of Tenth East Asia-Pacific Conference onStructural Engineering and Construction (EASEC-10), 3-5 August 2006, Bangkok, Thailand.(Vol. 6 Pg. 621-626)

[19] J. Khedari, B. Suttisonk, N. Pratinthong and J. Hirunlabh, New lightweight compositeconstruction materials with low thermal conductivity. Journal of Cement and ConcreteComposites 23 (2001), pp. 65–70.

[20] J. Khedari, S. Charoenvai and J. Hirunlabh, New insulating particleboards from durian andcoconut coir. Int. J. Build. Environ. 38 3 (2002), pp. 435–441.

[21] J. Khedari, P. Watsanasathaporn and J. Hirunlabh, Development of fibre-based soil–cementblock with low thermal conductivity. Journal of Cement and Concrete Composites Vol. 27Issue 1, 2005, pp. 111-116.


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