Wednesday, March 25, 2009

PMA - JKR Experiance

Poor quality of asphalt binder is one of the causes for early deterioration of asphalt concrete surface, especially with high traffic volume roads. During the past 15 years, rutting in conventional asphalt concrete highway due to the substantial increase in traffic volume has become major problem facing motorists. PWD of Malaysia have revised to tackle the problem by using 60-70 penetration grade asphalt instead of the usual 80-100. This, however, resulted in fatigue cracking and fretting and hence became a serious problem. Polymer modified asphalt has then been used to improve the asphalt cement properties. Asphalt concrete has more resistance to deformation, more stiffness and elasticity after the application of polymer modified asphalt. The mixture demonstrates high resistance to rutting, fatigue cracking and fretting. From the first modified asphalt concrete road pavement in Kelantan (Jalan PCB), it was found that the durability, stability, strength index and bond between aggregates and binder of the polymer modified asphalt were improved.

Sunday, March 15, 2009

INFO Kerja Penurapan Jalan

"JALAN YANG BARU DITURAP DAN SELESAI DIGELEK TIDAK BOLEH DIBUKA KEPADA TRAFIK SEHINGGA BAHAN TURAPAN TELAH SEJUK. PADA KEBIASAANNYA TIDAK KURANG DARIPADA EMPAT JAM(4 JAM) SELEPAS DIGELEK"

Saturday, March 14, 2009

Polymer Modified Asphalt (PMA)

Info From "http://www.semmaterials.com/"

What, How, Why?

The term "polymer" simply refers to a very large molecule made by chemically reacting many (poly) smaller molecules (monomers) to one another in long chains or clusters. The physical properties of a specific polymer are determined by the sequence and chemical structure of the monomers from which it is made. When polymers are added to asphalt, the properties of the modified AC depend on two things:
  • the polymer system used
  • the compatibility of the polymer with the asphalt.

Why modify?

Improvement in resistance to rutting, thermal cracking, fatigue damage, stripping, and temperature susceptibility have led polymer modified binders to be substituted for asphalt in virtually all paving and maintenance applications, including hot mix, warm mix - cold lay, cold mix, chip seals, hot and cold crackfilling, patching, recycling, and slurry seal. They are used wherever extra performance and durability are desired. In many cases they are selected to reduce life cycle costs. Polymer modified binders have allowed the use of techniques previously not practicable, such as micro-surfacing and using emulsion chip seals on high traffic roads.

Tuesday, March 10, 2009

Rocks

abstract from " A Guide to good quality control practices on asphalt production and construction"

Rocks are classified relative to their geological origins and these are termed Igneous, Sedimentary and metamorphic

1. Igneous Rocks

formed from hot liquid or magma, cooling either above or beneath the earth's surface.
examples are Grannite & basalt

2. Sedimentary Rocks

The action of wind or water on a rocks surface results in the formation of smaller particles. These particles are deposited on river or sea beds or depressions in the earth's surface. This sediment accumulates and is buried. Compaction and cementation over the years removes the air and water to form sedimentary rocks.
Typical example is Limestone

3. Metamorphic rocks

Heat, pressure and chemical substances deep beneath the earth's surface act on existing igneous and sedimentary rocks to form a new type called metamorphic rocks, example marble