1920-10-33

Advantages of Lime in Construction By TYRRELL B. SHERTZER, Construction Engineer Eastern Bureau Nat. Lime Ass n. THAT engineers, architects and constructors recognize the value of hydrated lime mixtures in conchete construction is evidenced by the rapidly increasing number of specifications calling for the admixture of hydrated lime in all classes of concrete work, and also by the recent railing of the Board of Standards and Appeals of New York City, noted in the American Contractor of May 8, 1920. Advantages. Briefly summarizing the advantages to be derived from the admixture of hydrated lime in concrete the following may be cited: Hydrated Lime: (1) Makes concrete much more plastic and workable, thus facilitating chuting and placing. (2) Reduces the amount of water necessary in mixing concrete, thus obviating the danger of drowirng cement, particles, and also overcoming the difficulties and known detrimental effects of evcessive free water. (3) Causes concrete to lie closer to the forms and reinforcement, thus giving more uniform and smoother faces, eliminating segregation and stone pockets, and reducing finishing costs. (4) Produces denser and more homogeneous concrete. (5) Acts as a preservative to the reinforcement. (6) Prevents separat'd! and settlement in carts and buggies. (7) Imports more uniform apparance as to sorface and color. (8) Is the most efficient integral watertightening medium as officially declared by the 11. S. Bureau of Standards, and is also the cheapest material available. That hydrated lime imparts the above mentioned properties to concrete has been observed and testified to by many of the leading professional and practical men of the country, as well as by practically all of the departments of the IT. S. Government dealing with construction matters. Highway Construction. In view of the rapid development of automobiles and the breakdown of our rail transportation system, good roads are today imperative, or the large majority of communities a concrete road provides the most durable and satisfactory type of construction. A number of state h’ghwav departments, county engineers, and municipal authorities have inveseigated the advantages to be derived from proper admixtures of hydrated lime in concrete used for highway and pavement construction, with the result that many of them have now standardized such admixtures in their specifications. After careful study and investigation, the affice of Public Roads, U. S. Department of Agriculture has approved specifications calling for hydrated lime admixtures on projects to which government aid is extended. Careful and systematic studies conducted by the Delaware State Highway Department ndicate that the following advantages are derived from the proper admixeure of hydrated lime in highway construction. (1) The compressive strength of the concrete is increased. (2) The concrete is placed and finished with less Work. (3) The concrete is made more impervious to moisture, thus protecting the subgrade and reducing* the internal stresses caused by alternate absorption and evaporation of moisture. (4) The war seems to be more uniform and decreased as compared with plain concrete. (5) Economy is effected in that 1-2-4 concrete with hydrated lime admixtures has proved more satisfactory than l-li/2 -3 concrete without hydrated lime. (6) Observations indicate that cracks are less frequent in concrete with hydrate lime admixtures than in the plain concrete. (7) The free water content is reduced and the surface runs of from the finished surface. Concrete Products. One of the rapidly growing uses for concrete is the production of concrete products, such as blocks, bricks, p’pe, battery boxes, etc. In order to facilitate the manufacture and to prevent excessive mold equipment being tied up, such products are generally made of very dry mixtures. Such dry mixtures are difficult to work, owing to the fact that there is not enough water present to provide lubrication or plasticity. Complete filling of the molds is also difficult w th the dry mixtures and requires an excessive amount of work. The loss due to imperfect mold filling* and breakage of green specimens on acount of lack of cohesion, is large. The admixture of hydrated lime to the mixes tised for the manufacture of cancrete products has in several instances, turned a losing venture into a paying business. Lime reduced to a paste or putty

is the most plastic of all materials used in construction. The experiences of many manufacturers of concrete products have conclusively demonstrated that the admixeure of hydrated lime provides workability in the mass and at the same time does not reduce the consistency to such an extent as to interfere with the rapid manipulation of the material jii the molds and out of them. As a matter of fact, it has been found that the labor required to fill and tamp the molds has been materially reduced, and as a consequence the rate of production has been increased. Experience has also demonstrated that the finished products are more uniform in texture and color, denser and more impervious, harder and more durable. Masonry Mortar. Lime has been considered one of the basic materials of civilization ever since it has been known that a mortar composed of lime and sand would hold stones and brick in place in buildings, enabling mankind to provide more comfortable and durable housing than the primitive skin and wattle huts. The oldest structural works of man such as the pyramids, anti many other prehistoric works, in Vuina, were bu\ilt fame mortar as the material for binding the individual structural units together. This mortar has resisted the ravages of the elements throughout the seucceeding centuries, thus demonstrating the durability of the material. The monumental structures of continental Europe were all constructed with lime mortar, giving further evidence as to the time-resisting value of the material, even when subjected to the severe varying climatic conditions. No structural material ever used by man has shown itself sifperior to 'properly prepared lime mortar made from lump or quick lime, as in encient and medieval times. Recent scientific investigations of the subject of mortars have conclusively demonstrated that even those composed of portland cement are greatly improved by the presence of lime. Tests conducted at Columbia University, New York C : ty, have conclusively proved that, a mortar composed of one part portland cement, one part limem, and six parts sand (all by volume) produces brick masonry which has a compressive resistance more than a third greater than can be obtained when only portland cement and sand are used in the volumetric proportion of 1-3. Other tests conducted by equally authoritative laboratories have proved also that both cohesion and adhesion are increased by the use of lime, and that the bedding of masonry, or in other words, the area of contact between the structural unit and the mortar bed, is greatly increased by the use of lime owing to the remarkable plasticity of lime putty. Another valuable property of lime, indicated by the tests at Columbia University, is its remarkable moisture-retaining power. Owing to this property the “suchtion,” or absorbent action of structural units, such as brick, exercises a much less deletriaus effect upon the mortar, due to absorbing the water from it. Lime Plaster. Soon after man discovered that he could build better hauses by binding durable units together with l’me mortar, his sense of refinement and inherent desire for order and decoration began to be awakened. He became dissatisfied with raugh interiors and so smeared the rough surfaces of his structures with some of the mortar. Thus the art of plastering was born. The chambers of the pyramids, the ruins of Pompeii, and other examples of ancient structures are plastered. At Pompeii and other ancient ruins lime plaster in many instances has resisted the ravages of time and the elements better than the surface of stone or brick to which it was applied. Many museums and private collections contain specimens of wonderful frescoes upon great slabs of lime plaster. which is was found possible to remove intact form the structural surface to which is was originalil applied. All of the remarkable examples of Greek, Roman, Byzantine, Florentine, Medieval, and Renaissance structures were plastered with lime plaster, to which were applied the priceless works of the ancient artists either by the frescoe or the “laid-in” method. The remarkable preservation of these art gems as regards both color and detail is irrefutable testimony as to the durability and stability of lime plaster. The interesting buildings of the Elizabethan period, which were plastered both inside and outside with lime plaster, and which have resisted the climatic conditions found in England during the intervening centuries, bear futher testimony as to the lasting quality of lime plaster. No substitute yet ) devised can compare with properly prepared lime plaster, as to durability, stability, cheapness, and sound deadening. Lime plaster can be worked to absolutely true surfaces and angles due to the fact that it remains plastic long enough to permit perfect working. Lime has a most remarkable sand-carrying capacity, thus making for economy. Lime plaster will dry out as rapidly as any other material but requires slightly longer to attain the same degree of hardness. It is perfectly feasible to run three-coat lime plaster work from the same scaffold as is done with other materials. When having a. new home built the average man gives no consideration to what is probably the most 17 TIIL CONCRETE AGE October, 1920.

important, element affecting his comfort and pleasure*-'namely, the plaster. The plaster of a home is more in evidence than any other single item, and unsatisfactory plaster or a plaster failure may cause more unhappiness and inconvenience than any other failure, aside from the foundation or roof. Let ns consider for a moment the qualities and properties which plastering in the home should possess. One of the objects of individual home building is to insure privacy both in the broad meaning of the word and also as regards personal and individual seclusion. It is, therefore, desirable to plaster with a material that will not transmit sound from room to room or from one part of the house to the other. In other words, it is desirable to use a sound deadening material. Lime plaster is such a material. It is essential to use a material that will provide at least a reasonable degree of fire protection. Such a material is lime plaster. It is essential to use a material that will provide a suitable, stable, lasting foundation for decoration by one of the several methods, such as painting, frescoe, or papering, without danger of disintegration, cracking or discoloration. Such a material is lime plaster. As the result of over two years’ study and investigatxm, the Architects of the Board of Education, for the city of New York, specifically call for lime plaster in all auditoriums to be constructed in future school houses owing to the superior acoustical properties of lime plaster. Many public gathering places have proved unsatisfactory from an acoustical viewpoint because of unfortunate selection in plastering materials and the use of hard, resilient, sound reflecting material instead of the more porous and sound-absorbing lime plaster. In conclusion it may truly be said tliat “Lime Is Eternally Essential,” that it is the oldest and most time tried of any of our materials of construction, and tliat fit was a considerable factor in the establishment of civilization, and the uplift of mankind from the sloughs of savagery and privation. New York Housing Conditions. Only such construction as will relieve the shortage of dwelling accommodations and such construction as is in the public interest, should be given building permits, says Mayor Dylan of New York City, urging that legislation be enacted authorizing some responsible body to pass on permits for construction. The Mayor's report on local housing conditions shows that at least 100,000 additional apartments are urgently needed to provide homes for the city’s population. A total of 12,662 apartments and houses are now under construction but to meet the normal demand a sufficient number of tenement houses must be erected each year to provide at least 50,000 apartments. Under the state constitution New York City has no power to construct municipal apartment houses and rent them to private parties, but an amendment to the constitution can be passed and the city could then go ahead with its building program in January. 1922. In tin* meantime, the Mayor says, there should be no standstill in the erection of homes and multi-family liouses. Atlanta’s Big Building Record. The prosperity of the South is clearly evidenced in the enormous amount of construction work now in progress in Atlanta or proposed for the near future, building permits issued for June having already reached a mark that will establish a new record for the city during any single month. While the Federal Reserve Bank’s curtailing of credit will doubtless have some effect on construction, it is not particularly noticeable as yet. Two of the largest building permits issued during June were for the new Metropolitan Theatre at Broad, Luckie and Forsyth streets, $350,000, and the new nurses’ dormitory to be constructed by the Georgia Baptists’ Hospital, $200,000. Two large building projects recently proposed include a new 400-room hotel at Peachtree and Kimball streets, to cost $1,500,000, and a new 10story office building at Edgewood avenue and Equitable place, to cost $1,500,000. C. P. Byrd, president of the Byrd Printing Co., purchased the property at Peachtree and Kimball streets for approximately $250,000, and made the announcement of the proposed hotel. The building will be 10 stories, and Mr. Byrd is now in consultation with architects regarding the plans. The cotton interests will erect the office building, which will be occupied in the main by cotton brokers and agents, and by the Atlanta Cotton Exchange, which plans the expansion of its activities. New Building Inspector. James Coles has assumed Ms duties as building inspector for Charleston, S. C., being the first official of the kind on the city engineer’s staff. This office was recently created, and is expected to result in improved building operations and a better building code. Mr. Coles is now checking up building permits, seeing that work authorized is carried out, according to the ordinances. Charleston has been doing a lot of construction, in spite of generally adverse conditions, and the inspector will have plenty of work to handle. 18 October, 1920. THE CONCRETE AGE

A Modern System of State Highways What it Means as an Aid in Getting Farm Products to the Consumer and Thus Reducing Living Costs. Extracts from an address by W. A. McGirt, President of the North Carolina Good Roads Association, delivered duly 23 before the North Carolina Press Association at Waynesville, N. C. are here given as of general interest in the cause of good roads. In part, Mr. McGirt said: There is no more serious problem before the nation today than that of reducing the cost of getting the products of the farm to the table of the consumer. We are told, on the authority of the Government, that farmers lose $300,000,000 yearly in marketing their crops because of bad roads. North Carolina’s sweet potato crop amounted to $13,000,000 last year, and $6,000,000 went to waste because of lack of transportation and organization. We should remember these facts in connnection with the high cost of living. You cannot neglect the farmer without seriously affecting every line of industry. Merchants, bankers and manufacturers are beginning to realize this, and many of them are now supporting legislation favoring the development of rural communities. The country can exist without the city, but it is not possible for the city to exist very long without a back country to feed and support it. Practically all wealth is traced to the soil, and the farms are the blood and sinew, the very life, of our State and Nation. Without them the pulsebeat of this .great nation would forever cease. What is the solution? How can we better rural conditions and remove all crop wastage? How can we improve our educational facilities and our health conditions and reach an assured position with regard to these fundamentals? After many years of close study of these problems, I am satisfied that a modern system of State highways will do more to bring quickly the needed changes than any other one thing, because it is a fact not to be disputed that with the advent of good roads there come quick communicat on and transportation, better churches, better homes, better schools, including consolidated schools in rural communities, better farms, including silos and barns, crops and increased cultivated acreage, less crop waste, and best of all, good roads mean a satisfied and contented rural population. The above statement is based on the result obtained by good roads in other States, and what has actually happened in the more progressive counties of this State that have already completed thc 7 r system of modern hard-surfaced highways. If von agree with me on the solution of many of our problems, the next question that naturally comes to our minds is, How can we secure a system of State highways? I would suggest for your consideration: First, the establishment of a State highway construction fund for the building of a modern system of State highways 'connecting county-seats and principal towns. This construction fund to be provided by an ad valorem tax supplemented by sufficient serial bonds, issued at such times and in such amounts as needed to meet economical expendtures. Seeon. the establishment of a State highway maintenance fund to be derived from a liberal license fee imposed on all motor-driven vehicles, the license fee to be graduated according to the horsepower and purpose of the vehicle, and to be used exclusively for the maintenance of State highways and for the support of the State Highway Commission. Third, the creation of a small though strong and representative, State Highway Commission, with a competent State highway engineer as its executive head. The commission to employ the best highway engineers obtainable, who, under the direction of the commission, shall locate, supervise and maintain the State system of hard-surfaced highways. Fourth, that the counties shall be relieved of the burden of building any portion of the State highway system. If any county has already constructed any county road as a section of such State highway, or any road is to be incorporated as a part of the State highway system, such county shall be reimbursed, either by the building of an equal amount and quality of county highway or by an equitable adjustment based on the original cost of sa : d road. Fifth, the employment of all able-bodied State prisoners in the construction and maintenance of the proposed system of State highways. Sixth, the necessity of a constitutional amendment, if such be necessary, for the exemption of bonds for roads and other public improvements from local and State taxation. No one will question the feasibility or the practicability of the plan suggested, other than that portion of it embraced in the question of the ability and willingness of our taxpayers to invest their money in a program which will certainly involve many millions of dollars. However, no road poTcy wi’l he successful which is not broad enough in its scope to provide an adequate system of hard-surfaced highways hauling into every section of the State. We should not make the oft-repeated mistake of underestimating the

cost of this comprehensive system of highways, for taxpayers have learned to have more confidence in getting some real return for their investment when estimates are large enough to offer some hope of the successful completion of a given undertaking. If we accept 5000 miles as an estimate for an adequate system of highways, we may also assume that the cost will approximate $150,000,000 which could Avell be distributed over a period of 10 or 20 years. I believe that the taxpayers of this State are able and willing to finance the undertaking necessary to place this State on a more solid basis for the future development of its resources. In substantiation of my statement, please permit me to quote you some figures wh'ch show the almost uirimited wealth of this great State: Last year (1919), we are told, the agricultural products of the State amounted to $750,000,000, this in spite of the fact that we have over 20,000,000 acres in the State that are not being used for any purpose. In 1917 the output of our manufacturing industries amounted to $655,000,000, and during the past year undoubtedly increased to well over a billion. The output of lumber, cordwood and other wood products amounted to well over $100,000,000. Our banking resources for 1918 were $222,000,000. Our deposits in savings banks in 1918, $61,000,000. We paid the Federal Government last year, in income, excess profits and special taxes, $102,812,648. Our State has now an investment of approximately $130,000,000 in motor vehicles, including automobiles and trucks, which is being added to at the rate of $130,000 a day. Few of these types of vehicle are confining their activities to the roads of any one township or county, but are users of inter-county or State highways. To relieve railroad congestion and for many other reasons the State and Federal government should go into the business of road building on a big scale. The United States Government should build the great trunk line highways through the States, and the States should build from county-seat to county-seat, thus leaving the counties to build their local systems which will serve as feeders to these main arteries of commerce. Counties should not be expected to participate in the construction of the State system. Local county roads are a necessary adjunct to the large trunk line State highways, and if counties will build their 45.000 miles of local roads, it is enough to ask of them. To be of greatest service to the farmer, and through him to the State, the State highways must be made available by a system of high-class county roads. The counties are not able to build both systems. Annual Meeting American Engineering Societies The Annual Convention of the American Society of Civil Engineers held in Portland, Oregon, August 10, 1920, adopted resolutions which provided, —“that the Board of Direction of the American Society of Civil Engineers be directed to submit at once the question of the American Society of Civil Engineers becoming a charter member of The Federated American Engineering Societies to referendum vote to the Corporate membership of the American Society of Civil Engineers as recommended by the Joint Conference Committee, said ballot to be accompanied by a copy of the Constitution and ByLaws of said Federation.” and “that the Board of Direction of the American Society of Civil Engineers be further instructed in event of a favorable vote on said referendum to proceed at once to take such steps as may be necessary for the American Society of Civil Eng'neers to become affiliated with said Federation. ” Lessons From Engineering Council. Tn connection with The Federated American Engineering Societies, two questions have arisen: 1. “If Engineering Council is a success, why should the proposed Federation supplant it?” and 2. “If Engineering Council is a failure, why should the Federation be organized along lines so nearly parallel? These are basic questions and worthy of the serious consideration they have received not only from the Joint Conference Committee when it was preparing : ts report but also from the Committee on Constitution and By-Laws of the Washington Organization Conference. When the Joint Conference Comittee, composed of conferees of four of the then five members-Societies of Engineering Council, considered the question of co-operat:on of these societies in matters of common concern to the engineer, the functions and accomplishments of Engineering Council naturally came under review. There were present as conferees, three members of Engineering Council; by invitation of the Committee, Council also had an offic:al representative present. The Committee decided that some form of com20 October, 1920. TH E CO N C RET E AGE