Types of concrete Regular concrete 1 commonly published

Types of concrete – Regular concrete 1. commonly published on packets of cement, typically using sand or other common material as the aggregate, and often mixed in improvised containers 2. strength - 10 MPa - 40 MPa 3. made by using 1 part Portland cement, 2 parts dry sand, 3 parts dry stone, 1/2 part water 4. Ratio - (1 : 2 : 3 : 0. 5) 9/3/2021 Building Materials Sofia Sebastian 1

Types of concrete – High strength concrete 1. compressive strength generally greater than 40 MPa 2. High-strength concrete is made by lowering the water-cement (W/C) ratio to 0. 35 or lower. 3. Often silica fume is added to prevent the formation of free calcium hydroxide crystals in the cement matrix, which might reduce the strength at the cement-aggregate bond. 9/3/2021 Building Materials Sofia Sebastian 2

Types of concrete – Stamped concrete an architectural concrete which has a superior surface finish. 1. Pigmenting - After a concrete floor has been laid, floor hardeners (can be pigmented) are impregnated on the surface and 9/3/2021 Building Materials Sofia Sebastian 3

Types of concrete – Stamped concrete 2. Textured moulding - a mold which may be textured to replicate a stone / brick or even wood is stamped on to give a attractive textured surface finish. 9/3/2021 Building Materials Sofia Sebastian 4

Types of concrete – Stamped concrete 3. Sealing - After sufficient hardening the surface is cleaned and generally sealed to give a protection. The wear resistance of stamped concrete is generally excellent and hence used in parking lots, pavements, walkways etc 9/3/2021 Building Materials Sofia Sebastian 5

Types of concrete – Vaccum concrete 1. The use of steam 2. The idea is the steam will remove the air that is trapped inside the concrete. 3. The steam will condense into water and will create low pressure, pulling out air from the concrete. 4. This will make the concrete stronger due to there being less air in the mixture. 5. A drawback is that the mixing has to be done in a mostly airtight container. 9/3/2021 Building Materials Sofia Sebastian 6

Types of concrete – Shot Crete 1. uses compressed air to shoot concrete onto (or into) a frame or structure. 2. applied overhead or on vertical surfaces without forming. 3. It is often used for concrete repairs or placement on bridges, dams, pools, it eliminates the need formwork. 4. Shot crete is also used for applications where seepage is an issue 5. often used as a quick fix for weathering in loose soil types 9/3/2021 Building Materials Sofia Sebastian 7

Types of concrete – Pervious concrete 1. contains a network of holes or voids, to allow air or water to move through the concrete 2. This allows water to drain naturally through it, and can both remove the normal surfacewater drainage infrastructure, and allow replenishment of groundwater when conventional concrete does not. 3. Pervious concrete can significantly reduce noise, by allowing air to be squeezed between vehicle tires and the roadway to escape 9/3/2021 Building Materials Sofia Sebastian 8

Types of concrete – Cellular concrete 1. combining all the good qualities of concrete and also having a material which is light in weight, easy to work, with a pleasant finish 2. The pre-formed foam is added to the cement slurry and mixed in the concrete mixer or in a continuous process. 3. ultra-light weight concretes which have a density and compressive strength very similar to that of wood. 4. They are easy to work with, can be nailed with ordinary 9/3/2021 Building Materials nails, cut with a saw, drilled with wood- Sofia Sebastian 9

Types of concrete – Glass concrete 1. The use of recycled glass as aggregate in concrete 2. aesthetic appeal of the concrete 9/3/2021 Building Materials Sofia Sebastian 10

Types of concrete – Asphalt concrete 1. form of concrete as well, with asphalt (bituminous materials) replacing cement as the binder 2. used in construction projects such as road surfaces, airports and parking lots. 9/3/2021 Building Materials Sofia Sebastian 11

Types of concrete – Geopolymer concrete Geo-polymer concrete 1. greener alternative to ordinary Portland cement 2. made from inorganic alumino-silicate (Al-Si) polymer compounds that can utilize 100% recycled industrial waste (e. g. fly ash and slag) as the manufacturing inputs resulting in up to 80% lower carbon dioxide emissions. 3. Greater chemical and thermal resistance, and better mechanical properties, 9/3/2021 Building Materials Sofia Sebastian 12

Concrete blocks 1. Concrete blocks are made from cast concrete, i. e. Portland cement and aggregate, usually sand fine gravel for high-density blocks. 2. Lower density blocks may use industrial wastes as an aggregate. Those that use cinders (fly ash or bottom ash) are called cinder blocks in the US. Clinker blocks use clinker as aggregate. 9/3/2021 Building Materials Sofia Sebastian 13