Cement Brick Research Articles

Caractérisation d'une maçonnerie composée d'éléments en aggloméré de chanvre

The tested masonry elements, made of an agglomeration of industrial hemp and inorganic binders, were prefabricated on a cement brick production with an objective to use them for light-weight load-bearing wall construction and for insulation purposes. The tests indicate that the load-bearing characteristics of such masonry construction is close to the present Swiss recommendations. Furthermore, the sound insulation characteristics are comparable to the numerous other traditional systems, but they are still not competitive compared to other existing systems from the point of view of thermal insulation.Key words: construction, brick, light weight, building materials, industrial hemp, mechanical properties, physical properties, sustainable development.

Use of porous lavas as supports of photocatalysts

Porous lavas, more precisely pumice stone, are promising supports for TiO 2 used as a photocatalyst. TiO 2 deeply penetrates into pores that favours its retention. Its deposition is convenient and facile and the photocatalytic activity is not significantly affected by the erosion of the surface. The immobilization of TiO 2 on pumice stone gave better results for the photocatalytic degradation of 3-nitrobenzenesulfonic acid than conventional sol–gel dip-coating on cement and red brick. A layer of pumice stone as pellets, fixed on a cement layer and impregnated with TiO 2 is used in a thin film fixed bed reactor, for the photocatalytic treatment of water.

Solidification/Stabilization of Dyeing Sludge Treated by Fenton Reagent Using Blast Furnace Slag and Fly Ash

ABSTRACT This study was performed to reuse of dyeing wastewater sludge treated by Fenton process through the solidification/stabilization technique. To solidify the dyeing sludge the industrial by-products such as blast furnace slag, fly ash and waste sand with cement were used. The laboratory scale and pilot scale test were conducted at room temperature to make construction brick which has high compressive strength and low leaching of heavy metals. The experimental results showed that blast furnace slag and fly ash could be used instead of cement and the final products satisfied the brick regulation of Korean Standard. The blast furnace slag increased the compressive strength and the optimum ratio of slag/dry sludge on dry basis was found 0.4. The solidifying agent of SB series could increase rapidly the compressive strength and the optimum ratio of solidifying agent/dry sludge on dry basis was 0.26 at which the strength was two times compared with non-added condition. The portion of waste and industrial by-products in matrix was over 80%. From the pilot test the optimum pressure in molding was 100 kgf at which the compressive strength was over 100 kg/cm2. And the compressive strength increased continuously to 160 kg/cm2 until 120 days curing time due to pozzolanic reaction. When SB-20 as a solidifying agent was used, the unconfined compressive strength of dyeing sludge could be obtained 110 kg/cm2which satisfied the regulation of cement brick in Korea Standard (KS).

Ursachen der Festigkeit alter römischer und gothischer Gebäude und die Mittel, gleiche Dauerhaftigkeit bei neuen Mauerwerken zu erhalten / Reasons for the strength of old Roman and Gothic buildings and ways how to achieve the same durability with new masonry

Abstract The Preussian Royal Directorate for Finance, Military and Property has published the following prize question in 1775: in which way depends durability of Gothic and Roman masonry on time, on specific local conditions, on the stones and mortars used, and on the design, the execution and curing conditions? And how is new masonry to be built in order to achieve the same durability? The text which has been selected for this award is presented in full length in this contribution. First some observations made in Roman buildings are described. The observations are explained based on Roman literature on architecture and buildings. The durability of frequently used mortar and stones is discussed. The preparation of durable mortars is treated in detail. Different types of masonry are described. In conclusion it is stated that for external renderings and for mortars in masonry exposed to humid conditions cement mortar, i.e. mortar made with lime mixed with puzzolanas as a mineral binder, are to be applied exclusively. Internal renderings can be made with plaster of Paris or lime mortar. In an appendix it is pointed out that the thickness of a wall has a major influence on durability. In Holland durable and thin masonry walls are being built, however. This is possible because high quality cement mortars and bricks burnt at high temperature (clinkers) are used

Natural radioactivity and radon exhalation rates in building materials used in Egypt

Natural and fabricated building materials commonly used in Egypt were surveyed for both natural radionuclides content and radon exhalation rate. These include raw as well as construction products. Concentration of natural radionuclides in all samples were determined by γ-ray spectroscopy with HPGe detector. For Radon exhalation rate measurements of fabricated samples, the seal can-technique has been applied using CR-39 plastic track detectors. The radiation hazard indices of the total natural radioactivity in the studied samples were estimated. The results were compared with the corresponding results of different countries and were found to be lying within the average world values. Radon exhalation rate in the studied samples varied between 197 (cement brick) and 907 mBq m −2 h −1 (blast furnace slag cement). The results of this survey suggest that, using blast furnace slag cement for pre-coating the internal walls of buildings in the Urban region of Egypt is discouraged and the replacement of clay brick by cement brick will be more healthy for the public.

APPLICATION OF THE PSTAR METHOD TO A MASSIVE TEST CELL FOR THERMAL PERFORMANCE EVALUATION

This paper studies the thermal performance of a small thermally massive test cell built by the Korea Institute of Energy Research (KIER) located in Daejeon, Korea. The cell is 3 m wide, 3⋅6 m long and 2⋅6 m high. It is built mainly with concrete and cement bricks. A partition wall divides the interior of the building (cell) into two zones: a living and a buffer zone. Space heating of the building is provided by coils carrying hot water imbedded in the massive floor. This case study was of special interest because the KIER test cell is significantly more massive than those previously tested using the same methodology by the National Renewable Energy Laboratory (NREL) in the United States. A series of short-term tests were conducted to evaluate the major heat flow terms which largely influence building performance. The test procedure and data analysis were carried out according to the PSTAR method developed by the NREL. Each test period was three days during which the building was unoccupied. The data measured with eight channels were used to renormalize an audit based simulation model of the building. Results show close agreements between the measured and renormalized values reflecting the effects of heavy thermal mass, whereas the simulation results from the audit description of the test cell deviate considerably. A long-term extrapolation has also been made from the weather data of Seoul TMY (Typical Meteorological Year) for the calculation of monthly heating and cooling loads. © 1997 by John Wiley & Sons, Ltd.

The Most Beautiful House in the World by Witold Rybczynski

310 Book Reviews TECHNOLOGY AND CULTURE The Most Beautiful House in the World. By Witold Rybczynski. New York: Viking Penguin, 1989. Pp. 211; bibliography. $18.95. When Witold Rybczynski was thirty-two years old, he was “struck with what seemed an irresistible urge” to build a wooden boat. A professor of architecture at McGill University, he was familiar with plans, blueprints, and modelmaking—and he was a passable carpen­ ter. But he needed a boatbuilding shed and decided to construct one himself. He bought a plot of land at the corner of an old orchard south of Montreal and with the help of a friend immediately poured the concrete foundation slab. He was then left with the task of designing and building the shed, a project that was gradually trans­ formed over the course of several years (and enough carpentry to satisfy him for a lifetime) into the design and construction of his own house. This book chronicles Rybczynski’s work and the transforma­ tion. Rybczynski’s last book was the provocative Home: A Short History of an Idea (New York, 1986), and I can think of no writer better suited to inform and entertain readers with a recounting of a boatbuilding shed-to-house project. As a detailed chronicle of design and construc­ tion, The Most Beautiful House in the World falls short of Tracy Kidder’s House (New York, 1985), but in other ways is much more satisfying. Kidder tells his story from several points of view—client, architect, and builder—and so does Rybczynski, insofar as he is all three. Since he is by vocation an architect, and a widely read one at that, the reader is provided with a deeper analysis of design intentions and decisions as well as of paths not taken. The shape of the shed and its framing, the slope of its roof, the placement of windows and doors, and the architectural design process permitted Rybczynski to reflect on a variety of topics in the history and theory of architecture: beginning with Nikolaus Pevsner’s famous distinction between “buildings” (a bicycle shed) and “architecture” (Lincoln Cathedral), he considers the invention of the lightweight wooden (or so-called balloon) frame; the history of North American and English barns; the “language” or semiotics of architectural elements and the relation of a building to its context; the relation between the representation of a building in plans, drawings, and models and the completed project; and the writings and work of architecture notables. These digressions—which at times seem rambling if not random— make up the most satisfying sections of the book. Especially interest­ ing are Rybczynski’s excursions into the anthropology of building, for instance: the Chinese practice offeng-sliui, the siting of a building in the natural landscape according to religious, astrological, and other notions so that the good fortune of its inhabitants and that of the TECHNOLOGY AND CULTURE Book Reviews 311 surrounding community are maximized; the rituals of the Nabdam tribe of northern Ghana for determining the feasibility of a given building site (a chicken is killed on the site; if it dies face down, the site is abandoned); the Greek and Roman practice of hepatoscopy, examining the liver of an animal sacrificed to a particular deity for favorable signs and omens concerning the chosen site; and the Hindu “science of dwelling”—sipasastra—and the rituals associated with the commencement of construction—khal muhrat. These examples re­ mind us that, throughout history and currently in other cultures, technologically based practices are often associated with symbolic rituals based on beliefs important in these cultures, a theme historians of technology have left largely to anthropologists and scholars of comparative religion like Mircea Eliade. Another digression—the most delightful of the book—reminds us of another neglected theme, the importance of technology toys in shaping the interests and abilities of would-be inventors, engineers, and architects. Rybczynski makes a historical survey of construction toys, from playing cards that might be houses to Friedrich Froebel’s building blocks, Ole Chris­ tiansen’s Lego blocks, Richter’s tiny cast cement bricks, A. E. Lott’s Italian marble blocks, Meccano and Erector sets, and Lincoln Logs, which the reader learns...

Temperature dependence of thermal conductivities and thermal diffusivities of composites using transient hot-strip method

Simultaneous measurements of the thermal conductivity and thermal diffusivity of four composite building materials, namely black marble stone, normal building stone, red sand brick and cement brick have been made at room temperature using the transient hot-strip method. The power supplied to these samples is quite large compared with that for loose building materials owing to their composite (brick) nature. The temperature dependence of thermal conductivity and thermal diffusivity of these materials has also been investigated in a temperature range from 10 to 60°C. Temperature stability is assured within 0.1°C by using a platinum resistance thermometer in the chamber containing samples and a digital voltmeter to record any variation in resistance. The results of these experiments show that there is a very slight variation in thermal conductivity and thermal diffusivity of these materials in this temperature range.

Lateritic soil—cement bricks for rural housing

The need to utilise local materials for the building industry in developing countries cannot be over-emphasised. Lateritic soils are abundantly available in the tropics and can be used for the manufacture of durable bricks. This paper reports on improvement of the strength of these bricks by addition of cement. Results show that to achieve optimal strength conditions, the soil-cement bricks require much less hard firing than plain bricks. Depending on the firing temperature and amount of cement used, the addition of cement could result in brick strengths of up to four times those with no cement added at the same temperature and at least two and a half times the maximum strength with plain bricks at any firing temperature.

Cementation of hydroxide precipitates containing certain radioactive elements

it is shown that the following radioactive materials can be incorporated into cement brick so as to form an integral part of the composition: precipitates consisting of ferric hydroxide, aluminum hydroxide, manganese hydroxide, a sulfate-silica mass, ash obtained by combustion of rags, paper, and wood. Systems (and the requisite qonditions) for cementation on the basis of these waste products have been developed. The cement consumption is 20–50% depending on the composition of the waste products. Some isotopes are incorporated more firmIy in cement brick than others (Nb and Ru are better incorporated than Cs and St).

Microwave absorption by water in building materials

Measurements are reported of the complex dielectric constants at wavelengths 10.0, 3.3 and 1.25 cm of specimens of concrete, mortar, hardened cement paste and brick (Hamill, Leicester Red, Burwell Gault and Fletton), loaded with water. Those in three of the bricks (H, L.R., B.G.) are interpreted in terms of dielectric mixture theory of three components, brick, air and rotationally free water absorbed in the cavities. Dissolved salt ionic conductivity is found to be unimportant; anisotropy at 10 cm wavelength is found in the Leicester Red brick. The dielectric properties of cement paste are believed to arise from water in the same state as that which produces the low frequency loss, rather than from rotationally free water. Absorption of free waves by walls is calculated from the data, and corresponds with experiment for concrete, but not for brick walls, on account of diffraction at mortar interstices.