YOUSIF RASHEED HASSAN MSc SIMENAR : SUSTAINABLE CONCRETE

: Sustainability sustainability means “meeting the needs of the present without compromising the ability of the future generations to meet their own needs”. It incorporates the environmental, economic and social considerations.

Elements of sustainability Environment EconomySociety - World Commission on Environment and Development, 1987

The Healthy Community Model SOCIETY ENVIRONMENT ECONOMY HEALTH

The sustainability of the concrete industry is imperative to the well-being of our planet and to human development. The concrete industry is committed to delivering higher quality buildings for human beings and businesses alike, which will enhance quality of life and working conditions and reduce their impact on the environment. The concrete industry is also responding to current concerns about climate change and energy efficiency.The enforcement of sustainable concrete and structures will further reduce short-term and long-term costs and be beneficial for our planet and environment

Principles of Sustainable Concrete and Structures In 1994, the International Council of Building (ICB) defined the concept of sustainable construction as the on “responsible for creating and maintaining” a healthy built environment based on the efficient use of resources and in the project based on ecological principles.Seven principles for sustainable construction have also been proposed by the (ICB) : (1) reduce resource consumption, (2) reuse resources, (3) use of recycle resources, (4) protection of nature, (5) elimination of toxics, (6) application of life cycle costing, and (7) focus on quality.

Concrete Concrete is an essential material with a worldwide estimated consumption of 33 (billion tones / year) of concrete, concrete is the second most consumed substance on Earth after water. A world without concrete is almost inconceivable!

Concrete Concrete is made from coarse aggregates, fine aggregates,water, cement and admixtures. These constituents are mostly available locally and in virtually unlimited quantities. Primary materials can be replaced by aggregates made from recycled concrete. Waste materials from other industries can be used to produce additions like fly ash, slag and silica fume

Concrete Concrete is one of the more sustainable building materials when both the energy consumed during its manufacture and its inherent properties in-use are taken into account.

cement A cement is a binder, a substance that sets and hardens and can bind other materials together. Concrete is represented by the cost of cement in the mixture

cement The construction industry is under increasing pressure to become ‘greener’ and help tackle the issues of global warming and diminishing natural resources. It is affected by a multitude of initiatives, including EU legislation, Government targets and the Code for Sustainable Homes.

cement A major priority for the producers of cement and concrete is to minimize carbon dioxide emissions and the cement industry has taken significant steps in this direction, particularly by improving the energy efficiency manufacturing Portland cement. Substantial reductions in carbon dioxide are also being achieved by the partial replacement of Portland cement by cementitious materials such as ground- granulated blast-furnace slag (GGBS) or fly ash. Currently, the use of 2.5 million tones of GGBS and fly ash as cement replacements every year, saving over 2 million tones of carbon dioxide emissions

The main sustainability benefits of replacement cement use are:

3- Savings in energy 4-Work the same work cement in terms of interaction and give the required strength 5- good workability provided 6- lower permeability 7- increase durability

Aggregate Aggregates are inert granular materials such as sand, gravel or crushed stone that are an end product in their own right. They are also the raw materials that are an essential ingredient in concrete. For a good concrete mix, aggregates need to be clean, hard, strong particles free of absorbed chemicals or coatings of clay and other fine materials that could cause the deterioration of concrete Aggregates, which account for 60 to 75 percent of the total volume of concrete

The impact of recycled aggregates on the sustainability of recycled concrete

4 - Some research has shown that the use of recycled rubble of concrete gives them two-thirds of the original natural resistance of concrete rubble 5- provided a good workability 6- provided a good durability

Admixtures Modern concrete contains, in addition to cement, gravel, sand, additions and air, one or more admixtures. Admixtures are chemicals added in very small amounts to concrete to modify the properties of the mix in the plastic and/or the hardened state. They are normally supplied as an aqueous solution to facilitate accurate addition through a dispenser. Today approximately 80% of ready mixed and precast concrete production is modified with a concrete admixture

Admixtures The quantity of admixture added is usually based on cement content and for most admixtures is in the range of 0.2 to 2.0% by weight. Even at this low content they have a powerful effect, modifying the water requirement, pump ability and setting properties in the fresh state, and specific hardened concrete properties such as strength, resistance to freeze -thaw cycles, sulphate resistance and other durability parameters.

concrete admixtures are classified into the following categories: Water reducing. Air-entraining Set accelerating Set retarding Water resisting

concrete admixtures are classified into the following categories: All other varieties of admixtures fall into the speciality category - their functions include corrosion inhibition, shrinkage reduction, alkali-silica reactivity reduction, workability enhancement, bonding, damp proofing and coloring

The main sustainability benefits of admixture use are: Optimised mix design - reducing embodied carbon dioxide, water content and energy by enhancing the effectiveness of the cement component Increased fluidity - reduces vibration noise and energy requirements during placing Reduced permeability - increases the durable life of the concrete

The main sustainability benefits of admixture use are: Reduced damage from harsh environments - including marine, freeze- thaw and sub zero situations Improved quality - better finish and reduced service life repair.

light weight concrete The concrete prepared by using coke breeze, slag as coarse aggregate is called light weight concrete. The concrete is light in weight and posses heat insulating properties

Advantages of Using LWC 1-Structural lightweight concrete offers design flexibility and substantial cost savings by providing: less dead load, improved seismic structural response, longer spans, better fire ratings, thinner sections, smaller size structural members, less reinforcing steel, and lower foundation costs

Advantages of Using LWC 2- Important characteristics of LWC is its relatively low thermal conductivity, a property which improves with decreasing density in recent years, The point is illustrated by fact that a 125mm thick solid wall of aerated concrete will give thermal insulation about 4 times greater than that of a 230mm clay brick wall. 3- Lightweight concrete precast elements offer reduced transportation and placement costs

Advantages of Using LWC 4- The bond between the aggregate and the matrix is stronger in the case of LWAC than in normal concrete. 5- Reduction of dead load indicates faster building rates and lower haulage and handling costs.