Calculation Of Concrete Cube, Bacteria

CHAPTER 3

METHODOLOGY

3.1 INTRODUCTION In this section of research methodology, will be described in more detailed on the scope of work regarding to the concrete cube, bacteria and calcium lactate with respect to the sample preparation, procedure, data collection and analysis. The flow charts on the scope of work are as follows:-

3.2 PREPARATION OF CONCRETE CUBE

3.2.1 CONCRETE MIX DESIGN

Before casting of concrete cube, the calculation of concrete mix design needed to be done in order to know the amount of water, aggregates, cement and sand to be used. Besides that, by doing concrete mix design, the appropriate water-cement ratio can be determined. The concrete mix design calculation is as table 3.1. The procedure of the concrete

TSB is a nutritious medium containing 17.0 g/L Tryptone, 3.0 g/L Soytone, 5.0 g/L NaCl, 2.5 g/L K_2 〖HPO〗_4 and 2.5 g/L glucose, with total of 30 g/L medium. This is a nutritious medium used for bacteria growth. TSB is a complex medium where in order to prepare 1 litre of TSB; 30 g of medium are going to be dissolved in 1 litre of water. The procedure involved in the preparation of 100 ml of TSB (Ratio of 3 g of the dehydrated TSB powder per 100 ml of medium) is as follows: Weight 3g of TSB powder and dissolve in double distilled water, 〖ddH〗_2 O. Place the conical flask on the magnetic stirrer to mix well until the powder completely dissolves. Transfer 10 ml of the medium to each 13*100mm glass spiral tube (or other suitable container). Make sure the cap of the tube is closed tightly. After transferring the medium, place all the glass spiral tube into the autoclaves for 15 minutes at 121ﹾC required for sterilization. After sterilization, remove the tube from the autoclave. Cool down the autoclaved tube before placing the stock in 4ﹾC refrigerator and avoid

The very important element needed to be considered in culturing and growing of bacteria reproduction are the nutrients, energy, water, suitable temperature, suitable pH value and suitable levels (or absence) of oxygen. The bacteria will be cultured and incubated with shaking at 160 rpm until mature for 24 hours in the nutrient media which are Tryptic Soy Broth (TSB) at 37ﹾ. The amount of the cell suspension will be measured at 600nm by using spectrophotometer. The cell concertation was then determined based on the equation below:-

Before the incubation of the bacteria for calcite precipitation, the bacteria were then washed from excess media by centrifugation and resuspension (put back into suspension) by clean tap water. The growth bacteria will be placed inside a tube and will be centrifuge for 10 minutes at 10000rpm. The pellet was taken then put again inside water,H_2 O vortex, and resuspend. The centrifugation process will be repeated for three times in order to obtain the cell pellet. This process called as repeated