Day 37 - Next Steps. Barn Boys prepare steps for the stepped, trench-fill foundations

.....and on and on they dig. 

Shepherd Howard once again entrenched. This time at my front door

At last, their oversize ruler pings a joyous note indicating that the Barn Boys have dug deep enough, to start 'stepping' the trenches* to prepare for Mr Easycrete's delivery of concrete and make a start on the foundations. That's after they've pumped out the rain water AGAIN!  

As BarnGirl's Barn is on a sloping site, it's necessitated step foundations - the concrete is stepped by securing form work into the trench.

Starting the step 'form work' for trench-fill foundations

One step at a time

 

Once the form work or steps have been positioned at the correct level, concrete (NOT cement) will be poured in, to a specific level. When this has 'cured' aka hardened, gone off, set, a layer of concrete blocks and bricks will be added and BarnGirl will start to see her barn going up. Hurrah!  I asked Boss Jon when the concrete would be set, oops, I mean cured. 'In about 24 years!' In reality, it would probably be fine for Inspector Walt and me to walk on the following day, along with the resident deer, badgers, rabbits, foxes and other local wildlife.

See If you're interested 2 and 3 below, for further info on concrete and curing. 

Who's the hooded man with the saw? 'tis Smiley Tim cutting board to create steps for trench fill foundations

Boss Jon with oversize ruler measuring foundation steps

  'Half a day in a trench. To think I could be in a warm, dry office!'

  

 

Mud n clay, mud n clay. Rain rain go away

Looking forward to Mr Easycrete's arrival with his lorry load of concrete.
Love
BarnGirl
xx

If you're interested....

1. *Trench-Fill Foundations
Traditionally the foundations for the walls of houses and similar buildings have consisted of strip foundations (generally unreinforced) with block or brick masonry up to damp proof course level. In ‘trench-fill’ narrow trenches are dug to the required foundation depth and completely filled with concrete.
This approach minimises the amount of excavation as access to lay blocks or bricks deep in the trench is no longer required. In addition, the trench is only open for a short time, leading to safer site working.
 


2. What is the difference between cement and concrete?
Although the terms cement and concrete often are used interchangeably, cement is actually an ingredient of concrete. Concrete is basically a mixture of aggregates and paste. The aggregates are sand and gravel or crushed stone; the paste is water and portland cement. Concrete gets stronger as it gets older. Portland cement is not a brand name, but the generic term for the type of cement used in virtually all concrete, just as stainless is a type of steel and sterling a type of silver. Cement comprises from 10 to 15 percent of the concrete mix, by volume. Through a process called hydration, the cement and water harden and bind the aggregates into a rocklike mass. This hardening process continues for years meaning that concrete gets stronger as it gets older.


3. What does it mean to "cure" concrete?
Curing is one of the most important steps in concrete construction, because proper curing greatly increases concrete strength and durability. Concrete hardens as a result of hydration: the chemical reaction between cement and water. However, hydration occurs only if water is available and if the concrete's temperature stays within a suitable range. During the curing period-from five to seven days after placement for conventional concrete-the concrete surface needs to be kept moist to permit the hydration process. new concrete can be wet with soaking hoses, sprinklers or covered with wet burlap, or can be coated with commercially available curing compounds, which seal in moisture. 

4. Can it be too hot or too cold to place new concrete?
Temperature extremes make it difficult to properly cure concrete. On hot days, too much water is lost by evaporation from newly placed concrete. If the temperature drops too close to freezing, hydration slows to nearly a standstill. Under these conditions, concrete ceases to gain strength and other desirable properties. In general, the temperature of new concrete should not be allowed to fall below 50 Fahrenheit (10 Celsius) during the curing period. 

5. Why do concrete surfaces flake and spall?
Concrete surfaces can flake or spall for one or more of the following reasons:

• In areas of the country that are subjected to freezing and thawing the concrete should be air-entrained to resist flaking and scaling of the surface. If air-entrained concrete is not used, there will be subsequent damage to the surface.

• The water/cement ratio should be as low as possible to improve durability of the surface. Too much water in the mix will produce a weaker, less durable concrete that will contribute to early flaking and spalling of the surface.

• The finishing operations should not begin until the water sheen on the surface is gone and excess bleed water on the surface has had a chance to evaporate. If this excess water is worked into the concrete because the finishing operations are begun too soon, the concrete on the surface will have too high a water content and will be weaker and less durable.

6. Will concrete harden under water?
Portland cement is a hydraulic cement which means that it sets and hardens due to a chemical reaction with water. Consequently, it will harden under water.

For further information on concrete basics, try this helpful site:
http://www.cement.org/basics/concretebasics_faqs.asp