DESIGN AND PRODUCTION OF CEILING BOARD USING PLASTER OF PARIS (P.O.P) GYPSUM MATERIAL

1.0     INTRODUCTION

          This project deals with the design and production of ceiling board using Plaster of Paris [POP] gypsum materials. Plaster of Paris [POP] is a white powdery mixture of gypsum. It has been named such because the first deposit of gypsum was found in Paris. This powder when mixed with water solidifies, but without losing its volume. During manufacturing process, the gypsum is heated and as such, it does not necessarily require any high heat treatment like ceramics and clays [Worrall 1999]. Because of its property to harden with just water, it is used in a number of areas, but most notably for molding decorative objects.

          According to Cornelis and Hurlbut (1985), plaster results from the calcinations of gypsum (CaS0₄.2H₂0), which partially dehydrates to produce a hemi-hydrate (CaS0₄.¹/₂H₂O). Although plaster of Paris a widely used today: its origin dated 9,000 years old and were found in Amotolia and Syria. It is also know fact those 5000 years ago, the Egyptians burnt gypsum in open-air fire, then crushed it into powder and finally mixed with water to make jointing material for the blocks of monuments, used model of plaster taken directly from the human body.

1.1     LITERATURE REVIEW

Plaster is one of the oldest known synthetic building materials: it was used by the Egyptians at least 4000 years ago in the construction of the pyramids, and the Greeks were producing decorative plaster work by 500 BC. The chemistry of the conversion of gypsum to plaster was also investigated early on by chemists such as Le Chatelier (1850 – 1936) and van’t Hoff (1852 – 1911).

Plaster is made by heating gypsum (CaSO4.2H2O) powder, thus converting it to calcium sulphate hemihydrate (CaSO4.½H2O). The hemihydrate is also known as stucco or Plaster of Paris. Probably so named because of the very large deposit of pure gypsum found beneath Paris. When water is added to the stucco, the material rehydrates to give a solid mass of gypsum. This rehydration is accompanied by an increase in temperature and a slight expansion of the plaster, causing the gypsum to perfectly fill a mould.

2.0     RESEARCH AIM AND OBJECTIVES

          The aim of this project is to design and produce ceiling board using Plaster of Paris (POP) gypsum materials.

          The objectives of the study are highlighted below:

• To produce durable light weight building material for ceiling
• To determine the strength of the ceiling board
• To determine its durability.
• To determine the volume and density of the ceiling board.

3.0     SCOPE OF THE STUDY

          The scope and limitation of this project is basically the design and production of ceiling board using plaster of Paris [POP] gypsum material. In the project , the density of the sample will be determined and the flexural test will be carried out to determine the strength of the sample made up of composite quantity of POP plaster, water and Fibre

[know as villas]

when subjected to loading.

4.0     JUSTIFICATION OF THE STUDY

The use of plaster of Paris [POP] gypsum ceiling board for ceiling finishing should be adopted and improved because the problems associated with asbestos, which have been used as ceiling finishes for years but with the use of plaster of paris [POP] gypsum material as ceiling finishes which offers sufficient sound insulation and considerable absorption of heart from the roof and hence provide employment opportunity to the producer.

5.0   METHODOLOGY

5.1     OBTAINMENT OF THE MATERIALS

          The materials obtained for the project design are plaster of Paris, fiber (villas), water and mould.

The used materials were obtained from the following:-

1. A local commercial POP material dealer Mevlon located at Ibrahim Taiwo Road Ilorin, Kwara State 
2. The mould used was obtained from Muhummed store at Olomoyoyo Emir’s Road, Ilorin.
3. Water supply was obtained from Civil Engineering Department Laboratory.

5.2     TOOLS USED FOR THE PROJECT ARE ENUMERATED THUS:-

1. Scrapper
2. Measuring tape
3. Mixing bowl
4. Bucket
5. Ranges
6. Saw 

5.3     MOULD’S PREPARATION

Already made mould (frame work) is used with dimension 710mm x 710mm x 14mm.

5.4     PREPARATION OF SEPARATOR

The separator is a mixture of premier soap and groundnut oil. It is applied to the mould for easy removal of the sample from the mould.

5.5     MIXING OF THE AGGREGATE

          Mixing is the process of thoroughly combining different materials to produce a homogeneous product. In this case water and P.O.P plaster are mixed to form a mortar with mix proportion 3 liter of water to 2kg of P.O.P plaster mixed vigorously to form a homogeneous mixture.

5.6     CASTING

The underlisted steps explain the casting of POP ceiling board:-

1. Firstly, the mortal was mixed in a clean container (mixing bowl). 
2. Water was poured into the container (mixing bowl) and plaster of Paris was sprinkled over it.
3. It took two minutes approximately before absorption.
4. Then hand was used to mixed the mortal and shake vigorously to obtain a fully homogeneous mixture.
5. The mortar was poured on the mould and sprayed to ensure it cover all the surface of the mould as first layer
6. Fibre/villas was added which serves as reinforcement on the poured mortar.
7. Similar mortar was prepared and poured on it and it was ensured that it covered the entire surface as well which serves as the second layer.
8. Finally, the sample was left for 13 – 15 minutes to set.

5.7     DETACHING OF THE MOULD

          The detaching of the ceiling board from the mould was done with the adoption of a special technique after the final setting. The setting period is very important and must be adversely followed to avoid breakages.

5.8     ABSORPTION OF WATER TEST

          Water absorption test was carried out on the sample to determine the water absorption capabilities. This test becomes pertinent to measure its response to water leakages from the roof after or during a down – pour. Seven samples was weighted and then immersed in water from one to seven days (1-7) of speculated in sample test, thereafter they were removed from the water and re-weighed as per the speculated days of immersion. The obtained data were recorded against each mass fraction and the mean obtained.

Ms = mass of immersed sample

Md = mass of dry sample