How to make ECO or interlocking bricks?
As we know that ECO blocks are becoming more and more popular for it can dramatically reduce the housing cost, about 30% to 37%. More and more countries are consider it as an cost saving construction material.
ECO blocks (also called interlocking blocks) are made by mixing soil, cement and sand mixture. The finished blocks even stronger than masonry stones. Someone made the experience that drop the ECO blocks and masonry stones from shoulder high, the ECO blocks remain good condition, while the masonry stone broke into two pieces.
Since ECO blocks are becoming so popular and strong enough to build houses, how can we make them?
1. Raw material preparation:
Soil, cement and sand.
1.1 Soil selection
The soil can’t contain too much clay, or the blocks will shrink and crack during curing. While it can’t contain too much sand too. Too much sand will make the blocks hard to handle, it may smash when you get them out of interlocking block machines.
1.2 Find the right soil
(1) Dig a 1m deep hole
(2) Look at the different soil layers. Does the soil look sandy or does it have lumps?
If it has lumps and cracks, it’s the kind of soil we need. If it is very sandy then dig deeper to find more suitable clay soil.
Note: DO NOT USE SOIL ON THE SURFACE! It contains too much organics. The reason is that organic matter continues to breakdown over time while sand, silt, and clay are much more stable and will not rot away.
1.1 Wash test
Take some soil in the hand and pour water onto it. Rub and squeeze.
A. If you feel gritty, there is a lot of coarse sand in the soil. If you feel slimy there is a lot of clay in the soil.
B. Wash your hands. If you can wash off the soil easily then there is much sand or silt. If it is difficult to clean off and leaves colour on your hand, then the soil contains a lot of clay.
1.4 Bottle test
Fill the bottle with 1/4 soil followed by 3/4 water.
Shake the bottle violently
Leave it for 24 hours for the soil to settle down.
Compositions: from up to bottom: organics, clay, silt, sand and gravels. Observe the proportions. There must be 10% to 50% clay and silt to make a block, ideally 15-35% silt and clay
2. Raw material ratio
2.1. Ratio
1) cement(10%)+ clay (90%) + water (appropriate)
2)cement(10%)+ viscous material (20%) + sand (70%) + water (appropriate)
〖viscous material:(shale powder,white lime)ect 〗
3)cement(10%)+ chemical accelerator(20%) + sand (70%) +water (appropriate)〖chemical accelerator:(Na2sio3,water glass）ect.（Note: ratio listed is just for reference and production ratio should be adjusted according to local situation）
3 BLOCK PRODUCTION
3.1 Sieving
You can make a simple sieve like the one in the photo or buy our roller sieve.
3.2 Raw material mixing with pan mixer (Do not allow blades to touch drum )
Firstly, start the mixer.
Secondly, add the soil with trolley into the mixer from a slope. Or you can buy a belt conveyor to convey the clay into mixer. Soil first, cement followed.
Note: no. 2, no. 4 and no. 6 are belt conveyors. They can connect two machines and convey soil into next machine.
Thirdly, dry stirring for one minute.
Fourthly. Slowly add water and stir for one minute.
Note: 1. Water should be sprayed slowly. DO NOT pour water into the same spot.
2. The soil -cement mixture must be used up within one hour.
3.3 Checking the moisture of the mixture
3.3.1 Squeeze the soil -cement mixture into a ball .
3.3.2 Drop the ball from waist high .
3.3.3 As what shows in the photo. Second one is the best to make ECO bricks and blocks.
3.4 ECO bricks blocks curing
Curing gives the ECO block durability and strength
Fristly, Stack the blocks 5 high and 7 wide (depending on the width of the plastic).
Secondly, Cover the ECO blocks, as soon as they are stacked. Never leave the ECO bricks blocks in the sun or wind uncovered, even when they are udner a shade.
Water the ECO bricks and blocks twice a day, in the morning& afternoon. Cover them immediately after watering. The ECO blocks are cured for 7-14 days and it will reach its highest strength after 28 days.
