Study On The Preparation Methods And The Performance Of Recycled Brick Aggregate Concrete

The exhaustion of resources caused by mining sand aggregate brings a growingproblem, looking for alternative sand and gravel aggregate is imminent. At the sametime, engineering construction in our country also entered a peak, engineeringconstruction scale expanded year by year, the number of construction waste generatedin the process of engineering construction has greatly increased, and how to manageand deal with these waste materials effectively becomes inevitable and the one mustbe solved of the major problems in the construction development.As the large numberof construction waste which waste concrete and waste brick accounted for abouteighty percent, this topic main research on the green concrete which waste brick usedas recycled aggregates. Using the waste brick of the construction waste produced bydemolition of brick mix structure for making recycled concrete, has importantsignificance for maintaining the sustainable development of concrete materials andenvironmental protection.The abandoned bricks which made of existing buildings demolished are usedinstead of part of natural rubble as coarse aggregate and experimental study wascarried out on the subject “The approach for the proportion design of recycled brickaggregate concrete”. Through the mixture ratio design, the rational use of waterreducing agent and admixture, the concrete slump adjustment technology measures, topreparation of recycled brick aggregate concrete. Research results show that themixture ratio design according to the characteristics of the recycled brick aggregatehigh bibulous rate, poor sturdiness, by adopting additional water method design themixture ratio of recycled brick concrete aggregate concrete is more reasonable.At the same time, studying in-depth on the recycled brick aggregate concrete’sworkability, compressive strength, flexural strength, modulus of elasticity anddurability including resistance to chloride permeability and carbonation resistance ofrecycled concrete. And found that28d compressive strength of recycled brickconcrete aggregate can meet the requirement of C40, the highest can reach45.28MPa.Considering concrete workability and strength, the best proportion is Group6in thispaper, which means regeneration aggregate dosage is30%, and fly ash replacingcement content of10%. According to research which recycled concrete slump iscontrolled between30mm-60mm, when the proportion of regeneration aggregate is30%, the fly ash content is10%, the compression strength of recycled brick aggregateconcrete is as high as50.14MPa. Apparent density r and cube compressivestrength is a good linear relationship.Using regression analysis to determine A, B inthe rubble recycled concrete aggregate strength calculation formula.In addition to brick aggregate dosage is50%, Z30, Z30F10, Z30F15and Z40, four groups concreteelastic modulus are all reaching the requirement of C40, and derive the relationship ofcompressive strength and elastic modulus. Durability mainly studies the recycledconcrete’s resistance to chloride ion permeability and carbonation resistanceperformance.Durability test results show that compared with natural concrete, thechloride ion permeability and carbonation depth of the recycled brick aggregateconcrete aggregate is increase slightly. With the increase of recycled brick aggregatecontent, carbonation depth and chloride ion permeability of recycled concreteincreases gradually.