involve over 300,000 structures or about 38 percent of the Nation's major highway structures. Concrete aggregate is an essential material for all bridges regardless of the type of construction materials used in the superstructure. Based on United States Bureau of Mines mineral market reports, total aggregate production for 1952 was as follows: The following are estimates of quantities, by classes, which were consumed by highway construction and maintenance activities in 1952: Material: Crushed stone__. Sand and gravel. Total_____. 1,000 tons 181,000 255, 361 16,000 452, 361 The highway take for 1952 was, therefore, about 62 percent of related aggregate production. Based on trends, it is estimated that total production of all classes of aggregates suitable for highway work reached a level of approximately 810 million tons in 1954. By applying the 62-percent factor to the estimated 1954 production, the total highway consumption amounted to approximately 502 million tons of which 357 million tons were used in highway construction. The maximum annual requirement during a $11 billion highway construction program is estimated at an additional 535 million tons, or about 150 percent in excess of 1954 highway construction requirements. This maximum requirement would not occur until the fourth year of the proposed program. Local shortages of aggregates will continue to exist in widely scattered areas of the United States, with long hauls of imported materials necessary. These areas are largely confined to delta topography and flat river valleys where bedrock is not available and where natural deposits are of a fine silty nature or have unfavorable characteristics. Sections of Louisiana, North Dakota, Kansas, and Nebraska are typical of the above conditions. In most regions, however, there are adequate reserves of sand, gravel, and stone for an expanded highway construction program of the scope proposed. Aerial photogrammetry and other recently developed methods for locating buried natural deposits give promise to the discovery of additional aggregate sources in some of the more critical shortage areas. The basic problem with regard to aggregate supply for an accelerated highway construction program is one of expanding production capacity. The question therefore arises as to the ability of the aggregate industry and highway contractors to meet the demands and to determine what increase is possible with existing plants and what additional equipment will be needed. With regard to commercial producers of crushed stone, an inquiry was directed to the regional vice presidents of the National Crushed Stone Association to determine what they considered to be the possible percentage increase in plant capacity between 1952 and 1956. The replies indicated that increases ranging from 25 to 100 percent were possible. It is believed that an average 40-percent increase in production for the 4-year period would not be unreasonable. It is also believed that the sand and gravel industry could match this increase in production. The supply of slag is dependent on the activity of blast furnaces. In order to accomplish this increase in production, it would be necessary to make minor plant additions, to add additional shifts in some areas and to make greater use of stockpiling in the winter months. In the New England area crushed-stone plants are normally shut down from December 1 to March 15. It seems reasonable to suppose that a 40-percent increase in production over the 1954 rate could also be achieved with existing plants by the fourth year of 1 Latest year for which production data are available. an expanded highway construction program. This would amount to about 324 million tons and leave a deficit of about 211 million tons to be provided with new equipment. Crushing and screening equipment would be needed for about half of the 211 million tons. Task force No. 4 of the American Road Builders' Association, which was primarily interested in new machinery and equipment requirements for the expanded program, has also studied this problem. It is the opnion of task force No. 4 that 560 additional portable crushing and screening plants will be needed in the maximum expansion year to produce the additional aggregates that requre such processing. An additional annual requirement of 560 crushing and screening plants is some 60 units over the peak capacity previously achieved by the manufacturers of such equipment. It is anticipated that the equipment industry will be fully capable of producing the additional aggregate-producing equipment once the program is firmed up and sufficient lead time is given. The conclusion is reached that sufficient aggregates can be produced to meet the needs of a $101 billion program if construction is accomplished at a gradually increasing tempo and extended over a period of 10 years. BITUMINOUS MATERIALS The expansion of the highway program to a $11 billion level will increase the use of bituminous materials appreciably. At the present time some 18 million tons of bituminous materials are being produced. Highway construction uses only a third of this. The remainder is used for highway maintenance, the production of roofing materials, and other purposes. There are, however, several sources from which the additional bituminous materials can be obtained. The major source is, of course, the refining of crude petroleum. Crude petroleum provides the basic asphalt for paving and for the production of cutbacks and emulsion and road oil. A second source is the tar obtained as a byproduct in the iron and steel and the manufactured-gas industries. The third source is the natural asphalts and rock asphalts produced in this country and abroad. The bituminous material supply possibilities will be discussed under three broad headings. (1) Petroleum refining The production of asphalt and asphalt products from petroleum has increased approximately 6 percent a year since World War II. Approximately 79 million barrels or 14,343,000 tons were produced in 1953. Another 400,000 tons of petroleum asphalt were imported. The production of this quantity was dictated by demand and was not limited by either the availability of crude petroleum or of refining and storage facilities. Asphalt is only one of the many products obtained from the refining of crude petroleum. The amount of asphalt obtained from a given crude can be varied by changing the amount of other products produced, such as residual fuel oil and coke. In addition, the various available crudes have different asphalt production potentialities. Asphalt production could be doubled without increasing or changing the crude supply and without changing the gravity of the crude petroleum being refined. The type of crude can, of course, also be varied at many refineries. Increased . use of heavier crudes would further increase production possibilities. Actually, in many areas of the country, heavy asphaltic crudes are in surplus supply for, in many cases, it has not been profitable to refine these high asphalt content crudes because of the lack of a residual market. The availability of asphalt on the eastern seaboard is particularly favorable for any foreseeable need. With crude sources now being utilized, production can be more than doubled with no additional refining facilities. In addition, a new refinery will go into production in this area in 1955 which has a potential capacity of 700,000 tons of asphalt per year. The Ohio-Great Lakes area is in an excellent position to supply all needs for asphaltic products. In 1954, four new refineries were built which produce asphalt in large quantities. One of these refineries is capable of increasing its present production 5 times or some 200,000 tons without additional facilities. The Southwest and gulf areas are capable of increasing asphalt production several times the 1953 volume by availability of heavier asphaltic crudes and increasing production to present capacity. The Middle Atlantic States are in a similar position. The Pacific coast area is capable of more than doubling present production because of the large surplus of heavy asphaltic crude available. At the present 61030-55-48 time asphaltic residuals are being stored in large quantities in California because of lack of a market. There are idle asphalt refineries in the Middle West and west coast that could be placed in operation if the market demanded. No shortage in storage for asphalt is foreseen because of the present program of increasing these facilities throughout the United States. New terminals and distribution centers are constantly being built from which delivery can be made by tank truck to almost any section of the country. It is conservatively estimated that current asphalt production could be increased by at least 16 million tons without any appreciable expansion of facilities and imports could be increased by at least 500,000 tons. (2) Coal distillation In 1953, some 828,729,000 gallons, approximately 3.5 million tons of tar, were produced from the distillation of coal. Of this, 127,333,000 gallons were burned as fuel. Only 700 million gallons or 3 million tons were available as bituminous materials. Tar is one of the many byproducts of coke and gas production A large part of the coke production is used in the production of steel. Tar production, therefore, varies with the production of steel. The expanded highway program will increase steel production, now running at about 73 percent of capacity, by 4 percent. It is possible therefore to obtain, if the use of tar as a fuel is curtailed, some 175 million gallons or 742,000 tons of additional tar during the expanded highway program. (3) Natural asphalts and rock asphalts Another source of bituminous materials is the asphaltic content of the rock asphalts mined in this country and the lake asphalts imported from such areas as Trinidad. In 1953, 1.4 million tons of rock asphalt were produced. This production can be considered as equivalent to the production of 98,000 tons of liquid bitumen. In addition, some 200,000 tons of lake asphalt are imported. The total material supplied from this source is therefore less than 300,000 tons. If demand increased, it could be raised to 500,000 tons or more, an increase in total supply of 200,000 tons. It should be possible therefore to increase the production of bituminous materials by over 17 million tons without substantial increases in productive or storage capacities. The expansion of the highway construction program will increase the consumption of bituminous materials by 7 million tons. It appears therefore that all the bituminous materials needed for the proposed construction program can be supplied without creating shortages in the highway maintenance supply or in the supply for other users of asphalt or asphalt products. STEEL The steel requirements of the expanded highway program are also shown on chart No. 1. Overall ingot capacity is not of course a problem since the total annual steel requirements of the expanded highway program will amount to only 5,500,000 tons and steel production, even at this time of the year when the seasonal steel demand is high, is running at an annual rate of 95 million tons, approximately 73 percent of capacity. The additional ingot production required for the expanded highway program (products plus scrap) amounts to about 4,600,000 tons which is only 4 percent of the total steel capacity. Ingot production is not therefore a problem. In addition, the steel requirement for the increased equipment production may amount to 1 percent of ingot capacity. This requirement will, however, come in the third and fourth years, somewhat in advance of the peak material requirements. It will not therefore increase ingot requirements appreciably. (1) Structural steel shapes Structural steel shapes will however be somewhat of a problem. Structural steel shape production capacity is estimated to be approximately 5,800,000 tons per year. The industry produced during the past year (October 1953 through September 1954) approximately 4,900,000 tons, or some 900,000 tons less than industry capacity. It is estimated that the current highway construction program uses 656,000 tons of shapes per year. Based on the 1954 production rate of 4,900,000 tons per year, the current use by other construction and industry amounts to some 4,200,000 tons per year. While some of the heavy steel-using construction levels are receding somewhat, it is thought that because of the general rise in the overall economic level, the use by other industries will remain at least as high during the next 10 years as it is now. The expanded highway program, starting in the fourth year of the program, will require an additional 1,564,000 tons of steel shapes per year or a total of 2,220,000 tons of shape per year. Since under current production levels there are some 968,000 tons of idle shape capacity, only 596,000 tons of additional capacity are needed and it is contemplated under the steel industry expansion program now underway to increase shape production by 600,000 tons. Completion of this program will therefore provide the necessary shape production capacity. The probable area use of the structural steel shapes is shown on the following table. It will be noted that major use will be in the northeast, middleAtlantic, and lake areas. These three areas will use about half the total. However, shapes can be shipped relatively long distances without appreciable increases in cost and therefore area production is not too great a problem. Highway construction requirements of structural steel shapes, by regions In the recent past, the supply of wide-flange shapes has been a most critical item insofar as highway construction is concerned. However, the production of this item has been expanded during the last 2 years, and it is estimated that the steel industry now has the capacity to produce about 2,200,000 tons per year. Current estimates also indicate that the present production rate of wide-flange structural shapes is about 2 million tons per year. Highway construction now uses about 368,000 tons and the use in other construction and maintenance is approximately 1,632,000 tons. It is expected that the expanded highway program will in the peak construction years use some 1,246,000 tons, or about 878,000 tons more than is now being used. The area use of the wide-flange shape is shown in the table on the foregoing page. As stated previously, present capacity exceeds production by some 200,000 tons. It should not be necessary therefore to expand production by more than 678,000 tons. In addition, the 600,000-ton expansion of shape capacity now underway is in the wide-flange area. When this is completed and considering that other uses hold at about the present level, the estimated requirements will exceed production by only 78,000 tons. Additional expansion in this amount should not prove a problem. (3) Plate Highway construction uses only a small part of the plate production and, unless other demands change, the supply of plate should be ample. As shown on chart No. 1, the additional requirements of plate under the peak construction level will amount to 385,000 tons. Another 200,000 tons may be required for additional equipment production. Plate production in August of this year was down to 365,000 tons, and the monthly capacity is about 650,000 tons. All the additional plate required for the highway program could therefore have been produced in less than 2 months. (4) Reinforcing bar Reinforcing-bar consumption will be increased materially by the expanded highway program. However, reinforcing bars are a product that can be produced either on the mills normally assigned to that production or on most of the mills normally assigned to the production of other types of bars. This fact is illustrated in the following table of reinforcing-bar production, shipments, and capacity. It will be noted that in the years 1951, 1952, and 1953 the annual production exceeded the rated production capacity. The additional production was performed on those mills normally assigned to the production of other types of bars. It is estimated that the industry capacity for the production of bars other than reinforcing amounts to 14 million tons. The current production rate for these products amounts to approximately 11 million tons. There is therefore some 3 million tons of idle bar-mill capacity. Much of this capacity, at least two-thirds or some 2 million tons, could be used for the production of reinforcing bars. In the latest year for which full records are available-1953-only 100,000 tons of this capacity was used for bar production. It must be considered therefore that at least 1.9 million tons of idle reinforcing bar capacity is now available. If the demand for other bars and for reinforcing bar in other construction industries does not increase materially, this is more than enough capacity to supply the additional 1.3 million tons needed for the expanded highway program. It is also expected that before the highway demand can increase to that level, sometime in 1959 or 1960, the steel industry will increase their bar-production capacity. It does not appear probable, therefore, that there will be any shortage of reinforcing bars during the construction of the expanded highway program. It is possible, however, that there will be some expansion needed in the bar fabricating industry. Expansion of this industry should not, however, be too difficult. (5) Welded-wire fabric and mesh reinforcement The supply of wire-fabric reinforcement for pavements and of wire-mesh reinforcement for reinforced-concrete pipe is another very critical problem. Wire fabric or mesh reinforcement has three principal uses: Reinforced-concrete pavements, reinforced-concrete pipe, and building construction. While there are some major differences between the different types of fabric or mesh, and some of the larger sizes cannot be produced on the smaller machines, there is a large amount of production capacity on which fabric can be produced for any of the three uses. The following table shows the welded wire reinforcement capacity and shipments for each year since 1945. |