Dust Preventives And Road Binders

PREFACE THE object of this book is primarily to furnish road engineers with a working knowledge of the characteristic properties of dust preventives and road binders now in use, and to develop certain fundamental principles relative to their selection and application. During the past few years there has been a rapidly growing demand for such information, which has so far been met in a not altogether satisfactory manner. The subject of dust prevention and road preservation is at present in a transitional state, and there is unquestionablymuch yet to be learned regarding the effect of certain properties of road binders upon the results obtained in practice. It is hoped, however, that thisworkmay serve as a basis for further development and that it will prove of some assistance to those who are interested in the use of such materials. The conclusions as presented are based upon experience which the author has acquired both in the laboratory and in the field in the past five years of his service with the United States Office of Public Roads. During his connection with this office he has had under his personal supervision the examination of practi- cally all varieties of road binders and their use under varying conditions in many parts of the United States. Throughout this book the mention of trade names as applied to the results of examination of road binders has for the most part been purposely avoided for the reason that different lots of these products have not as a rule shown definite and uniform character- istics. The ideas of producers, with reference to the manufacture of their materials, are undergoing a process of evolution, and in spite of the present lack of uniformity it must beadmitted that a general tendency is being exhibited toward the improvement of these materials. The author here wishes to express his indebtedness to Mr. L. W. Page, Dr. A. S. Cushman and Mr. C. S. Reeve for their kind assistance and advice in the preparation of this book, and also to those authors, hereafter referred to, from whose works he has quoted. WASHINGTON, D. C., February i, 1910. PREVOST HUBBARD. TABLE OF CONTENTS Chapter Page I. DUST PREVENTION AND ROAD PRESERVATION i II. CLASSIFICATION OF DUST PREVENTIVES AND ROAD BINDERS 27 III. INORGANIC DUST PREVENTIVES AND ROAD BINDERS 39 IV. INORGANIC DUST PREVENTIVES AND ROAD BINDERS continued .... 72 V. ORGANIC NON-BITUMINOUS DUST PREVENTIVES AND ROAD BINDERS 103 VI. HYDROCARBONS 112 VII. BITUMENS EMPLOYED AS DUST PREVENTIVES AND ROAD BINDERS.. 131 VIII. PETROLEUM AND PETROLEUM PRODUCTS 143 IX. SEMI-SOLID AND SOLID NATIVE BITUMENS 178 X. APPLICATION OF PETROLEUM AND ASPHALTIC MATERIALS 198 XL TARS AND TAR PRODUCTS 229 XII. THE APPLICATION OFTAR AND CONSTRUCTION OF BITUMINOUS MAC- ADAM 275 XIII. THE EXAMINATION OF BITUMINOUS ROAD MATERIALS AND INTER- PRETATION OF RESULTS 324 XIV. METHODS OF TESTING BITUMINOUS ROAD MATERIALS PROPOSED OR ADOPTED BY AMERICAN SOCIETIES 373 XV. SELECTION OF DUST PREVENTIVES AND ROAD BINDERS 384 APPENDIX 400 vii DUST PREVENTIVES AND ROAD BINDERS CHAPTER I. DUST PREVENTION AND ROAD PRESERVATION. Introduction. The prevention or suppression of road dust and the preservation of roads are undoubtedly two of the most important problems which to-day confront road engineers. Pub- lic attention in these matters has been aroused to such an extent that a demand for less dusty and more lasting roads than those of thepast is becoming more insistent every day...