建筑垃圾細料生產流動化回填材料的性能

魏建軍 張金喜 王建剛

摘要：以灰砂比0.03、0.05和0.08，粉砂比0、0.05、0.1、0.15和0.2為設計參數，對建筑垃圾回填材料進行設計。通過試驗對回填材料的流動性（流動度、泌水率）、無側限抗壓強度以及應力應變曲線、本構關系模型和彈性模量等進行研究。研究結果表明：回填材料的流動度受水固比影響較大，兩者接近線性關系；流動度在200～250 mm范圍，泌水率在4%～8%之間；回填材料抗壓強度與灰砂比和水固比之間存在很好的冪指數關系；回填材料應力應變曲線形狀與普通混凝土的相似，在此基礎上提出回填材料的本構關系模型；回填材料無側限抗壓強度與彈性模量之間存在很好的指數關系。

關鍵詞：建筑垃圾細料；流動化回填材料；本構關系；應力應變曲線；彈性模量

中圖分類號：TU52；U416.212

文獻標志碼：A 文章編號：1674-4764（2016）03-0096-08

Abstract：A new type of backfill materials using recycled brick and concrete waste as fine aggregates was designed with three cement-to-sand ratios （C/Sa） and five fly ash-to-sand ratios （FA/Sa）. A series of measurements were conducted to investigate the fluidity and bleeding and mechanical properties including uniaxial compressive strength， stress-strain relationship， constitutive relation model and elastic modulus. The results showed fluidity had linear correlation on water-to-solid ratios（W/So）； the range of the bleeding rates was in 4%～8% when the fluidity was within 200～250 mm. The compressive strengths had an exponential relationship to the cement-to-sand ratios and water-to-solid ratios. A constitutive relation model was put forward to describe the stress-strain relationship curve of backfill material on the base of the model of the concrete. The relationship between the unconfined compressive strength and elastic modulus was established， which could be used to calculate the modulus of backfill materials by the compressive strength directly.

Keywords：recycled fine aggregates of brick and concrete waste；flowable backfill materials；constitutive relation；stress-strain relationship curve；elastic modulus

建筑垃圾細料是建筑垃圾在回收利用過程中經分揀，破碎、篩分后得到的粒徑范圍在0～5 mm的集料。目前，建筑垃圾細料主要來源有兩個：一是拆遷后的廢磚混結構，二是廢棄的混凝土或鋼筋混凝土結構。磚混結構生產的建筑垃圾細料主要是破碎的粘土磚和水泥砂漿顆粒和粉末，其中粘土磚的成分較多。廢棄混凝土結構生產的建筑垃圾細料中主要是破碎的水泥砂漿顆粒和骨料顆粒以及粉末等（如圖1、圖2所示）。由磚混結構生產的建筑垃圾細料因其強度低，吸水量大等原因多用于生產再生磚。

流動化回填材料是以0～5 mm細料為基礎，加入適當比例的水泥、粉煤灰，加水制備出可以實現自流平和自密實功能的材料。……