无砂混凝土生态护坡

No-Fines Concrete as Ecologic Stream Bank Erosion Control

Yuewen Huang1 and Xiong (Bill) Yu2,

Abstract

No-fines concrete is a pervious concrete obtained by eliminating the sand from normal concrete mix. Compared with conventional concrete, no-fines concrete has unique properties desirable for various applications. Because of the present of large voids, no-fines concrete has lower density, cost and thermal conductivity; smaller dying shrinkage, no segregation; larger contaminant retaining capability; reduced capillary movement of water. Non-fines concretes are used for construction of pavement, storm water control utilities and green house. This paper discusses the application of no-fines concrete as an ecology preservative method for stream bank erosion control. Soil erosion is an important factor that can trigger the instability of an embankment. A sustainable revetment should provide soil erosion protection without significantly changing the ecologic environment. The strength of no-fines concrete provides sufficient protection against scour of the embankment. Although grasses are found to be hard to survive with ordinary types of bank revetment, especially when subjected to periodic inundation from river water level variations, the large pore spaces of no-fines concrete protect grass seeds and incur amenable environment for grasses to grow. By installing artificial access holes in the no-fines concrete revetment, the ecologic conditions can be preserved to the maximal extent. The designing criteria and durability of no-fines concrete revetment are discussed. This paper also provides an example application of no-fines concrete revetment that achieved the desirable ecologic effects.

Introduction

Erosion control is important from a variety of environmental considerations. Excessive river bank erosion not only posses hazard to the engineered structures adjacent to the bank, but also contribute significant amount of sediment from the tributary river. This ultimately can lead to high solids concentration, excessive nutrition and pollution in the river. Proper river erosion control is needed to prevent these potential environmental hazards and to keep the existing ecosystem. Erosion control involves the use of engineering measures to maintain the sustainable ecosystem.

Concrete has been widely used to construct the engineering structures. Its advantages include the high strength and low cost. It is also widely available. Special types of concrete are currently being developed such as self-consolidating concrete, fiber 1Senior Engineer, Guangzhou Investigation Design and Research Institute of Water Conservancy & Hydropower, Guangzhou, Guanggong, China, 510640, huangyuewen1973@

2Assistant Professor, Department of Civil Engineering, Case Western Reserve University, Cleveland, OH 44106-7201, xiong.yu@, 216-368-6247