8/8/2019 6. House Made of RHA .......
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Industry & Business: House made of rice hull ash found to
lastPosted on Thursday, November 27 @ 11:52:06 PHT by crpd
What have long been regarded as waste and disposable could be
the ultimate answerto the problems of house builders and engineers
who have suffered long enough from
mounting cost of house construction materials.
The proof could be seen in the model house built out of ordinary
Portland cement bondedwith rice hull ash (RHA) and lime. The
RHA-lime house is one of the three model housesconstructed using
indigenous materials, which up to now stands proud and tough since
itsconstruction in 1987 alongside UP Film Center, UP Campus in
Diliman, Quezon City. TheRHA -lime served as additive to cement
sand bricks or hallowblocks used for the exterior andinterior walls
of the model house. University of the Philippines Building Research
Service(UP BRS) Director Nathaniel B. Diola said that the study on
the use of RHA-lime in buildingconstruction was confined to small
non-bearing block types since the materials are designedto benefit
the low-income families. The model houses with a floor area of 39
sq. m each wereturned over by the Department of Science and
Technology-Philippine Council for Industryand Energy Research &
Development (DOST-PCIERD), that funded the study, to the full
careand responsibility of UP BRS just recently. According to Engr.
Diola, various studies havebeen conducted to determine the
resistance of the materials to fire, weelvil, and mould. Theresults
are indeed promising, expressed Engr. Diola while citing how the
locally producedmaterials withstood harsh weather condition and
other corrosive elements like mould andvermin as attested by many
consumers and adoptors. UP BRS researcher Roberto Sorianoexplained
that the materials were subjected to load-bearing test for small
block types ofhouses and surprisingly passed. The technology
sparked interest from local constructionengineers and architects
who were awed with the results of studies that verified
RHAperformance as potential substitute for silica fume- an
important binding material ofpozzolan or cement. The adoption of
such kind of locally-produced technology should bemaximized and
sustained given the fact that resources are renewable, environment
friendlyand in great abundance, Diola added. Latest statistics show
that more than 150,000,000 metrictons of rice hulls are generated
each year throughout the world. However, Mr. Sorianoadmitted that
the use of rice hull for building houses is no longer a new
technology as it isbecoming popular even in developed countries.
The study conducted by Dr. Paul A. Olivierof Engineering,
Separation and Recycling Department in Louisiana, found that rice
hulls havethe lowest percentage of total digestible nutrients (less
than 10%) of all cereal by-products.This would mean that rice hull
has resilient quality to resist moisture penetration and
fungalactivities. In his paper, Dr. Olivier explained that rice
hull has an unusual high percentage ofsilica and crude fiber that
give the hull a very tough elastic property. One basic
considerationin building homes, no matter how big or small, is the
materials resistance to fire. Anyonewho has tried to set fire to
rice hulls understands how difficult they are to burn, since
aircannot flow freely through a pile of rice hulls to provide the
oxygen needed to initiate andsustain rapid combustion, Dr. Olivier
explained. The turnover ceremony coincided with thelaunching of
Compendium of Indigenous Building Materials and Technologies
(CIBMAT) ofUP BRS. CIBMAT is a database containing results of
research and development works overyears on indigenous building
materials and technologies and their performances andapplications.
(Mary Charlotte Fresco, STII S&T Media Service)
