#TITLE_ALTERNATIVE#

• Main Author: MARCELA TRIYANTI (NIM 13702022), MARIA
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/10846
• Institution: Institut Teknologi Bandung

Stone for outdoor building purposes usually experience natural weathering process up to a certain degree. This deterioration comes from its interaction with the physical, chemical or biological environment. However, the presence of acid rain will accelerate the degradation process of stone surface. Salts are some of the most damaging agents resulted from the reaction of certain elements with sulphuric acid in air. One of the examples is Na2SO4 salt, that has two forms i.e.; anhydrous salt thenardite (Na2SO4) and decahydrate mirabilite (Na2SO4. 10H2O). The salts that accumulated inside will produce internal pressures that caused spalling, flaking and eventually lead to further deterioration of the stone.<p> <br /> <br /> <br /> <br /> <br /> To prevent the deterioration mentioned above, 3 types of commercial acrylics were used and observed to coat the natural sedimentary stone surface and undergone weathering process simulation using Na2SO4 salt according to AASHTO T-104 and ASTM C-88 standards. Acrylic has a transparent property and solvent based that make it suitable to be applied on stone surface. The coating should be able to cover the surface and easily penetrate through the pores without changing the aesthetics.<p> <br /> <br /> <br /> <br /> <br /> From SEM microstructure observations and water repellent property measurements, it is found that type III coating showed better performance than the two other types. It penetrated from the surface and has a wetting angle of nearly 58 degree. From the soundness test using 225g/L Na2SO4, all of the coated samples showed a 50 percent higher resistance than the uncoated stone samples. Further investigations should be carried out to study the effect of acrylic resistance as a coating material against the other environment factors.