Testing and Specification of Drymix Mortar in Singapore

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  • Topic: Concrete, Strength of materials, Deformation
  • Pages : 17 (3276 words )
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  • Published : December 28, 2012
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TESTING AND SPECIFICATION OF DRYMIX MORTAR IN SINGAPORE

ABSTRACT

Singapore is a small island country, but has won renown as uncorrupted government and high quality products. Independent testing and inspection played a very important role for this achievement. The Housing and Development Board (HDB) is the sole public authority in Singapore and was set up as a statutory on 1 February 1960. Within 45 years, it built more than 700,000 flats housing approximately 86% of the population. Every year, around 40,000 new flats (about 400 blocks) are built up to meet the demands. In March 1992, HDB launched the 15-year main upgrading programme (MUP) to vying the finishes and facilities of old estates up to the standard of those in the new towns. The upgrading programme is a conscious effort by the government to provide a better living environment, strengthen existing community ties and enhance the value of our flats. The potential size of the upgrading program is approximately 370,000 units spread across 20 years, which works out to be 350 blocks per year. To ensure and maintain the high standards of the housing quality, drymix mortar is extensively used in the new and upgrading projects. In this paper, several types of drymix mortar used in Singapore public housing projects, such as: repair mortar for repairing of spalling concrete, prepacked plaster, internal and external skimcoat, normal floor screed and waterproofing floor screed, self leveling screed, and tile adhesive are discussed. The development of the requirements and specifications for the above drymix mortar are studied and analyzed. The effect of different factors on the drymix mortar is also described. It also outlines the methods and measures used to inspect and control the quality of application.

KEYWORDS

Mortars; Cement and concrete technology; Construction materials; Screed; Repair materials; Tile adhesive; Waterproofing; Skimcoat; Tile grout

INTRODUCTION

In 1964, the Singapore government introduced the Home Ownership Scheme to give citizens an asset in the country, a means of financial security and to hedge against inflation as it protests against rising rents. Home ownership also helps to contribute to the overall economic, social and political stability of the country. Since then, within 45 years, the government of Singapore, through its sole public authority HDB (Housing and Development Board of Singapore), has built 700,000 flats housing 86% of the population. Of the people living in HDB flats, nine out of ten own their own homes.

As pure cement mortar and concrete have some disadvantages such as delayed hardening, low tensile strength, large drying shrinkage, low chemical resistance and massy site management, poor quality control, etc, in order to overcome these disadvantages, many attempts have been made [1]. One such attempt is drymix mortar, which is made by the modifying ordinary cement mortar with polymer additives such as latexes, redispersible polymer powders, water-soluble polymers, superplasticizers and etc. Consequently, the properties of drymix mortar are markedly improved over conventional cement mortar [1].

To ensure and maintain the high standards of the public housing quality, drymix mortar are extensively used in the new and upgrading projects of HDB housing. In this paper, several types of drymix mortar used in Singapore public housing projects, such as: repair mortar for repairing of spalling concrete, prepacked plaster, internal and external skimcoat, floor screed and waterproofing floor screed are discussed.

The development of the requirements and specifications for the above drymix mortar are studied and analyzed. The effect of different factors on the drymix mortar is also described. It also outlines the methods and measures used to inspect and control the quality of application.

PREPACKED MORTAR MIX FOR PLASTERING

General

Plastering is intended to conceal unevenness in the...
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