Buildings

If your mix will require some amount of "man-handling" to properly place, a slightly wetter mix will make that easier. A drier mix is nice when forming curbs and inclined surfaces, or if you need to get the surface finished and nicely troweled in a hurry.

A standard size wheelbarrow will hold a manageable size mix using 2:4:6 (simply doubling the formula.) This is enough concrete to fill a large post hole

For a very small batch, use a 3/8" minus gravel. For a larger batch you could use 3/4" or even 1" minus if you need to stretch your sand and cement.

16 shovels of sand,7shovels aggragate(small rock),and on 90lb.bag Portland cement,4 to 7 gal. clean water.

Place above dry mix in suitable mixing conatainer (such as a wheelbarrow), add water slowly while turning the dry mix with a shovel or hoe. Continue adding water until mix has desired consistancy. Slightly 'dryer' than pancake batter is my preference.

a small child's swimming pool is what i have used for a long time their cheap and disposable ( I take mine to the recycling drop off after they crack)

The old Italian way is to place the cement and sand mixture in a pile on a flat surface. Using a shovel make a hole in the center, creating a ring. Pour water in the center and start bringing the dry material into the center. Keep doing this until the material has become completely wet. Continue to turn the mixture over with the shovel combining everything into a firm but moist consistency. To test if your mixture has enough cement in it, pull some out with your index finger and turn it upside down. If it sticks then you're good; if it falls off you have too much sand. Please note that cement WILL burn through your skin, so make sure you wash your hands.

you can also use a 5 gallon pail. add about 2 quarts of water to the pail , add approx. 40 # of concrete mix, than add about 2 quarts more water, than mix with a landscape shovel by by twisting in the bucket, till you have a pancake thickness.

A classic concrete recipe is one shovelful of Portland cement to two shovelsful of sand to three of small rock. You want ROCK, not gravel--gravel is graded for size, and using rock of varying sizes gives the concrete more strength since the little rocks interlock with the bigger ones. Anyway, you want a wheelbarrow to mix it in, a mortar hoe (it's got two holes in the blade) to mix it with and forms to put it in.

This is a method on how to place concrete underwater, this method place a big role in offshore concreting, since cement looses its strength and fade away under water, Tremie method is to be used. Tremie Concrete is done by using a formwork/pipe which will have one end of the formwork/pipe above water and other bottom end immersed under the water and with the help of gravity.

A tremie is a watertight pipe, generally 250mm in diameter, having a funnel shape hopper at its upper end and a loose plug at the bottom or discharge end. The valve at the discharge end is used to de-water the tremie and control the distribution of the concrete. The tremie is supported on a working platform above water level, and to facilitate the placing it is built up in 1 to 3.5m section.

During the concreting, air and water must be exclude from the tremie by keeping the pipe full of concrete all the time; and for this reason the capacity of the hopper should be at least equal to that of the tremie pipe. In charging the tremie a plug formed of paper is first inserted into the pipe as the hopper is filled the pressure of fresh concrete forces the plug down the pipe, and the water in the tremie I displaced by concrete.

For concreting, the tremie pipe is lowered into position and the discharge end is kept as deeply submerged beneath the surface of freshly placed concrete as the placed concrete as the head of concrete in tremie permits. As concreting proceeds the pipe is raised slightly and the concrete flows outwards. Care should be taken to maintain continuity of concreting without breaking the seal provided by the concrete cover over the discharge end. Should this seal is broken, the tremie should be lift and plugged before concreting is recommended. The tremie should never be moved laterally though freshly placed concrete. It should be lifted vertically above the surface of concrete and shifted to its new position.

When large quantities of concrete are to be placed continuously, it is preferable to place concrete simultaneously and uniformly through a battery of tremies, rather than shift a single tremies from point to point. It has been recommended that the spacing of tremies be between 3.5 and 5m and that the end tremies should be about 2.5m from the formwork. The risk of segregation and non-uniform stiffening can be minimized by maintaining the surface of concrete in the forms as level as possible and by providing a continuous and rapid flow of concrete.

How is the Underwater Concrete Mixes?

For Structural concrete following must be considered

• Coarse Aggregate: Gravel of 3/4" (20mm) max. size. Use 50-55 % of the total aggregate by weight.
• Sand, 45-50% of the total aggregate by weight.
• Cement: Type II ASTM (moderate heat of hydration), 600 lbs/yd3
• Pozzolans: ASTM 616 Type N or F, 100 lbs/ yd3
• Water/Cement Ratio: 0.42 (0.45 Maximum).
• Æ’Water-Reducing Admixture (preferably it is also plasticizer): Do not use superplasticizers.
• Æ’Air-Entrainment Admixtures: To give 6% total air.
• Æ’Retarding Admixture: To increase setting time to 4-24 hours, as required.
• Æ’Slump: 6 1/2" ± 1"
• Æ’This mix will develop compressive strength in the range of 5,600 - 7,000 psi at 28 days.

Insulating your home can reduce those high energy bills which will only increase as the price for energy continues to rise unabated.

Why Insulate Your House?

Heating and cooling account for 50 to 70% of the energy used in the average American home. Inadequate insulation and air leakage are primary causes of energy waste in most homes. Insulation:

• saves money and our nation's limited energy resources
• makes your house more comfortable by helping to maintain a uniform temperature throughout the house, and
• makes walls, ceilings, and floors warmer in the winter and cooler in the summer.

The amount of energy you conserve will depend on several factors: your local climate; the size, shape, and construction of your house; the living habits of your family; the type and efficiency of the heating and cooling systems; and the fuel you use. Once the energy savings have paid for the installation cost, energy conserved is money saved - and saving energy will be even more important as utility rates go up.

This fact sheet will help you to understand how insulation works, what different types of insulation are available, and how much insulation makes sense for your climate. There are many other things you can do to conserve energy in your home as well. The Department of Energy offers many web sites to help you save energy by sealing air leaks, selecting more energy-efficient appliances, etc.

The following information comes from Witold Rybczynski's book: One Good Turn: A Natural History of the Screwdriver and the Screw. ISBN 0-684-86729-X

The threading of the screw was invented by Archimedes (b.~287 BC, d.~212 BC) to create the water screw, used for lifting water for irrigation. This was the first human use of the mechanical helix.

The earliest published evidence found by Rybczynski of screws as we know them, threaded, with heads shaped for driving by a tool, and used to fix two work pieces together, is in a manuscript known as The Mediaeval Housebook, thought to be written in southern Germany between 1475 and 1490. This manuscript shows leg irons and manacles fastened with slotted screws.

Screws, while being difficult to manufacture relative to nails and rivets, have a strong holding capacity even in thin work pieces, and can easily be removed and reused without damage to them or the pieces they fix together.