Self compacting concrete (SCC) can be classified as an advanced construction material. The SCC as the name suggests, does not require to be vibrated to achieve full compaction. This offers following benefits and advantages over conventional concrete. Improved quality of concrete and reduction of onsite repairs. Faster construction times. Lower overall costs. Facilitation of introduction(…)
Special Concrete
Special concrete provides information on which are used in modern times, for increased strength and construction of skyscrapper or special structures. This include roller compacted, fibre reinforced, light weight, sulphur impregnated, bioconcrete, papercrete, recycled aggregate, self compacting, reactive powder,.ferro cement, silica fume, flyash, ready mix concrete.
PROPERTIES OF HARDENED SELF COMPACTING CONCRETE
Following are the properties of hardened self compacting concrete: 1. Compressive strength of Self Compacting Concrete In all SCC mixes compressive strengths of standard cube specimens were comparable to those of traditional vibrated concrete made with similar water -cement ratios – if anything strengths were higher. In-situ strengths of SCC are similar to those of(…)
MATERIALS FOR SELF COMPACTING CONCRETE
Following are the materials for self compacting concrete: Cement for self compacting concrete All types of cement conforming to EN 197 are suitable. Selection of the type of cement will depend on the overall requirements for the concrete, such as strength, durability etc., C3A content higher than 10% may cause problems of poor workability retention.(…)
PROPERTIES OF LIGHTWEIGHT CONCRETE
Properties of Light Weight Concrete The most significant property is reduced weight at no sacrifice in strength. Structural lightweight concrete available today are rotary kiln expanded shale, clay or slate (roughly 80% of structural use) and sintered expanded shale or clay (20%) provides the same compressive strength as normal weight aggregates with approximately the same(…)
FLOWABLE FILL CONCRETE
Flowable fill refers to a cementitious slurry consisting of a mixture of fine aggregate or filler, water, and cementitious material(s), which is used as a fill or backfill in lieu of compacted earth. This mixture is capable of filling all voids in irregular excavations and hard to reach places (such as under undercuts of existing slabs), is self-leveling, and hardens in a matter of a few hours without the need for compaction in layers.Flowable fill is sometimes referred to as controlled density fill (CDF), controlled low strength material (CLSM), lean concrete slurry, and unshrinkable fill.
REQUIREMENTS OF CONCRETING IN SPECIAL CASES
Sometimes concreting is required in Special Cases such as cold weather, hot weather, deep lifts, mass concrete, along coastal areas, underwater concreting etc. For these special cases, following requirements should be considered before placement of concrete. Concreting in deep lifts Placing of concrete in lifts exceeding 3m in columns and 2m in walls is in(…)
BIOCONCRETE
Why Bioconcrete? Problems in normal concrete: Cement, main ingredient = ‘Non-sustainable’ Yearly consumption : – millions of tons of cement in a single country – millions of tons of sand – millions of tons of gravel Environmental impact: 10%of world CO2 production due to cement production Liable to early-age crack formation / degradation 1. Loss(…)
SILICA FUME CONCRETE
CHARACTERISTICS OF SILICA FUME 1. Physical Properties Diameter is about 0.1 micron to 0.2 micron Surface area about 30,000 m²/kg Density varies from 150 to 700 kg/m³ When its density is about 550 kg/m³ it is the best suited as concrete additive 2. Chemical Composition Contains more than 90 percent silicon dioxide Other constituents are(…)