Concrete is an immensely popular building material composed of aggregate bonded together by fluid cement that cures slowly over time, making it one of the world’s most widely used construction materials.
Concrete slabs Melbourne is created by mixing cement, sand and small stones together with water before pouring it in place. Concrete is extremely hard-wearing and versatile – not to mention relatively cheap and plentiful!
Cement
Cement is an essential ingredient of concrete. It bonds the aggregate (such as sand/crushed rock fines and coarse), water, additives such as pozzolans or superplasticizers and reinforcement materials to form strong and durable structures.
Based on the type of cement chosen, different properties can be achieved for concrete. Sulfate-resistant cement features a lower heat of hydration so it doesn’t react immediately with water; its strength builds slowly instead. This can help to minimize damage from sulfate attack in underground and marine structures like groundwater systems, sewerage treatment plants and coastal piers.
Crystalline admixture cement reduces permeability by creating insoluble needle-shaped crystals that fill capillaries and micro-cracks to block pathways for water and contaminants to enter, making ready-mixed concrete less permeable to water or contaminants. It can also be found in products such as insulating mortars and insulated cement composites with fillers. New technologies and innovations continue to advance cement technology’s sustainability, strength and applications; for instance advanced concretes can absorb carbon dioxide during their production process for carbon storage!
Aggregates
Aggregates, composed of materials like sand, gravel, crushed stone or recycled aggregates that make up 60-75% of concrete mix, must be robust and hard particles without chemicals or coatings that could degrade its quality when mixed with cement. They must be processed to provide consistent size distribution between coarse and fine materials for optimal performance.
Aggregates play an essential role in concrete’s strength and durability, especially its compression strength. Coarse aggregates contribute to this by strengthening compression strength of concrete while helping reduce curing-related cracking; fine aggregates add bulk, workability and wear resistance as well as controlling drainage of excess water from mixes.
Size and composition of aggregates have an enormous influence over key properties of concrete, such as its permeability, volume stability, thermal expansion, workability and pumpability. Furthermore, absorption rates, surface moisture content levels, specific gravity ratio and reactivity must all be taken into consideration during mixing to reach an ideal water-to-cement ratio.
Water
Concrete can be found almost everywhere we look – from building foundations and streets, sidewalks and even your car! Concrete is an extremely hard material made by mixing aggregate (such as various kinds of sand and small stones), cement, water and an active chemical process called Hydration together to form one material.
Water usage in concrete production plays a pivotal role in its workability, compressive strength, permeability and watertightness, durability and drying shrinkage properties. Therefore, it is imperative that producers of concrete have access to an ample supply of water that they can effectively utilize for their production process.
Large ready mix producers are already mapping their water use, identifying opportunities to reduce usage and working with regulators to demonstrate their commitment to environmental stewardship. Not all producers, however, possess the resources required to monitor every drop they use; those that do usually recycle a significant percentage of process water for reuse in concrete production processes. This water must first be clarified, neutralized and purified prior to being recycled back into use again.
Mixing
Concrete mixing involves thoroughly mixing all ingredients until a uniform mass forms, producing consistent strength, durability and workability in the finished product. This essential step in construction can either be performed manually or using machine mixers.
Civil engineers can tailor the composition of concrete mixes to meet specific specifications by employing various admixtures and altering ratios between cement, sand and aggregates – this form of design-mix concrete.
Giatec’s Concrete Hub app makes creating the concrete mix necessary for their project requirements easy. It calculates and displays each ingredient required and the water/cement ratio so users can increase or decrease strength and durability of their final product as desired. Users may also add chemical admixtures such as water reducer or air-entrained admixture for their mix.