The Pneumatic Flow Mixing Method

The pneumatic flow mixing method was developed to stabilize dredged soil and surplus soil for promoting their beneficial use in 1999. The pneumatic flow mixing method is a new type of the ex-situ cement stabilization techniques, in which dredged soil and surplus soil is mixed with a relatively small amount of chemical binder without any mixing paddles and blades in a pipeline. When a relatively large amount of compressed air is injected into the pipeline, soil can be separated into small blocks. When binder is injected into the pipeline, the soil block and binder are thoroughly mixed by means of turbulent flow generated in the soil block during transporting. As this method has many benefits - rapid and large scale execution can be conducted with low cost - it has been applied to many land reclamation projects, backfilling behind earth retaining wall projects and shallow stabilization projects using dredged soils and surplus soils.The Pneumatic Flow Mixing Method is a useful reference tool for engineers and researchers involved in admixture stabilization technology everywhere, regardless of local soil conditions and a variety in applications.

1 An overview of admixture stabilization – Evolution of pneumatic flow mixing and the scope of the book1 Introduction 2 Cement admixture stabilization techniques2.1 Basic mechanism of cement admixture stabilization2.2 Classification of cement admixture stabilization techniques2.3 In-situ mixing techniques2.4 Ex-situ mixing techniques3 Development, mechanism and applications of the pneumatic flow mixing method 3.1 Development of the method 3.2 Mechanism of the method 3.3 Soil material suitable for the method 3.4 Applications of the method 4 Scope of the textbook References 2 Factors affecting strength increase 1 Introduction 2 Mechanism of cement stabilization 3 Influence of various factors on the stabilization effect 3.1 Influence of the characteristics of the binder 3.2 Influence of the characteristics and conditions of soil 3.3 Influence of the mixing conditions 3.4 Influence of the curing conditions 4 Prediction of strength References 3 Engineering properties of stabilized soils 1 Introduction 2 Properties of stabilized soil mixture before hardening 2.1 Physical properties 2.2 Mechanical properties (strength characteristics) 2.3 Mechanical properties (consolidation characteristics) 3 Properties of stabilized soil after hardening 3.1 Physical properties 3.2 Mechanical properties (strength characteristics) 3.3 Mechanical properties (consolidation characteristics) 3.4 Environmental properties 4 Properties of stabilized soil subjected to disturbance/compaction 4.1 Physical properties 4.2 Mechanical properties (strength characteristics) 5 Engineering properties of cement-stabilized soil produced in-situ 5.1 Flow value of field stabilizedsoil 5.2 Mixing degree of field stabilized soil 5.3 Effect of transportation distance 5.4 Effect of placement 5.5 Heterogeneity of dredged soil 5.6 Property of stabilized ground 6 Summary 6.1 Properties of stabilized soil mixture before hardening 6.2 Properties of stabilized soil after hardening 6.3 Properties of stabilized soil subjected to disturbance/compaction 6.4 Engineering properties of field cement-stabilized soil References 4 Applications of the pneumatic flow mixing method 1 Introduction 2 Improvement purposes and applications 2.1 Applications of the method 3 Selected case histories of the method in Japan 3.1 A field test on long-distance transport (field test) 3.2 Shallow layer construction at Nanao Port 3.3 Field test on the strength of stabilized soil placed underwater 3.4 Backfill in deep water 3.5 Land reclamation for Central Japan International Airport 3.6 Land reclamation for Tokyo/Haneda International Airport 3.7 Land reclamation using converter slag 3.8 Backfill behind breakwater – for settlement reduction (field test) 3.9 Backfill behind breakwater – for settlement reduction (field test) References 5 Equipment, construction, and quality control and assurance 1 Introduction 2 Equipment 2.1 System and specifications 2.2 Air pressure feed system 2.3 Binder supplier system 2.4 Pipeline 2.5 Placement equipment 2.6 Control equipment 3 Construction procedure 3.1 Preparation of site 3.2 Field trial test 3.3 Construction work 4 Quality control 4.1 Quality control before production 4.2 Quality control during execution 4.3 Quality assurance References 6 Geotechnical design of stabilized soil ground 1 Introduction 2 Design strength 2.1 Relationships of laboratory strength, field strength and design strength 2.2 Design flow for field and laboratory stabilized soil strengths and mixing condition 3 Geotechnical design 3.1 Earth pressure of stabilized soil ground with infinite width 3.2 Earth pressure of stabilized soil ground with a finite width 3.3 Bearing capacity of stabilized soil ground 3.4 Liquefaction of stabilized soil 3.5 Soil volume design References A Japanese laboratory mix test procedure 1 Introduction 2 Testing equipment 2.1 Equipment for making specimen 2.2 Soil and binder 3 Making and curing of specimens 3.1 Mixing materials 3.2 Making a specimen 3.3 Curing 3.4 Specimen removal 4 Report 5 Use of specimens References

Masaki Kitazume is professor of Geotechnical Engineering at theDepartment of Civil and Environmental Engineering at Tokyo Institute of Technology, Japan. Hehas over 35 years of experience in research and teaching of soil stabilization, ground improvement and foundation engineering, and published several text books on the design and quality control and assurance of ground improvement techniques including the deep mixing method and the sand compaction pile method.