Showing papers on "Mortar published in 1989"
229 citations
TL;DR: In this article, an equivalent material approach is presented for the computation of the elastic properties of brick masonry, where a stacked brick-mortar system consisting of a series of parallel layers which behave elastically is introduced.
200 citations
TL;DR: In this article, a comprehensive test program was developed to examine the potential for using the ash as a fine aggregate in mortar, and the strength characteristics of mortars prepared from sludge ash with addition of fly ashes (both classes C and F) and varying amounts of cement and lime were cured under standard laboratory conditions for periods of 1, 3, 7, 14, and 28 days before testing for compressive strength.
Abstract: Sludge ashes produced by the incineration of municipal sewage wastes are becoming increasingly difficult to dispose of in landfills, and there is a resulting increase of interest in disposal by inorporation in building materials. In the present study, a comprehensive test program was developed to examine the potential for using the ash as a fine aggregate in mortar. The strength characteristics of mortars prepared from sludge ash with addition of fly ashes (both Classes C and F) and varying amounts of cement and lime were cured under standard laboratory conditions for periods of 1, 3, 7, 14, and 28 days before testing for compressive strength. The results indicate that the addition of sludge ash adversely affects the strength behavior of mortars. Although partial substitution of sludge ash with fly ash gave improved results, strengths were always less than those obtained from control mortars using sand. Addition of fly ashes also improves mortar workability. The addition of lime in place of cement reduces strength.
66 citations
DOI•
01 May 1989
TL;DR: In this paper, the durability properties of concrete and mortar based on a special type of alkali-activated slag called F-cement were studied. And the microstructure was found to possess a high occurrence of microcracks that had an obvious influence on the flexural strength and rate of carbonation.
Abstract: This paper studies the durability properties of concrete and mortar based on a special type of alkali-activated slag called F-cement. The microstructure was found to possess a high occurrence of microcracks that had an obvious influence on the flexural strength and rate of carbonation. The rate of chloride-ion diffusion was about 30 times lower than in the portland cement concrete. Salt scaling was found to depend solely on the water-to-binder ratio and is independent of the air content. Early freezing takes place when the strength exceeds 5 MPa, and F-mortar shows high chemical resistance against solutions of sodium, calcium, and magnesium chloride.
62 citations
DOI•
01 May 1989
TL;DR: In this paper, the authors describe how rice husk ash (RHA) was obtained under different burning conditions from 400 to 1200°C, and the changes in the properties of the RHA were investigated using microanalytical techniques.
Abstract: This paper describes how rice husk ash (RHA) was obtained under different burning conditions from 400 to 1200°C. The changes in the properties of the RHA were investigated using microanalytical techniques. When RHA obtained at different burning conditions was added to cement paste or mortar, several properties such as hydration, setting time, porosity, and strength revealed changes and these changes are described.
51 citations
TL;DR: A typical domestic sewage was characterized and used in this article as mixing water, and setting time, air content, specific gravity, and strength tests were performed on cement paste, mortar, and concrete specimens made with distilled water.
Abstract: Reviews of the characteristics of domestic sewage and refinement in its composition upon biological treatment imply its suitability for use in concrete technology. A typical domestic sewage was characterized and used in this study as mixing water. Setting time, air content, specific gravity, and strength tests were performed on cement paste, mortar, and concrete specimens made with distilled water showed that untreated domestic sewage increases the initial setting time, entrains air, and reduces the strength of mortar and concrete, and therefore is not recommended for use in concrete technology. However, average biologically treated domestic wastewater is inistinguishable from distilled water when used as mixing water.
51 citations
TL;DR: In this article, the authors investigated the effect of the amount of bleeding water on the strength of the upper area of a concrete sample and concluded that the strength is not only affected directly by the bleeding water but other areas may be affected as well.
Abstract: As the height of concrete increases, the amount of bleeding water increases, This increse in bleeding water is directly proportional to height when the concrete is lower but becomes nonlinear in comparativley higher examples Obviously, the strength of the upper area of the specimen is affected directly by the bleeding water but the other areas may be affected as well In general, it is accepted that the strength of concrete is complicated by the consolidation of cement paste and aggregate Considering these facts, bleeding tests were carried out on cement paste, mortar, and concrete of various heights, and respective formulas were concluded to calcualte the amount of bleeding water Special attention was given to concrete specimens; strength tests were done at each height and compared to the amount of bleeding water
47 citations
TL;DR: In this paper, the effect of heating/cooling cycles on the durability of concrete made from available limestone aggregates in the Arabian Gulf countries was investigated and the results indicated that the experimentally determined values of the coefficient of thermal expansion vary from 5.07 to 9.99 × 10 −6 /°C.
39 citations
Patent•
06 Apr 1989TL;DR: In this paper, a foamable, 2-component mortar composition is used to fix tie bars and similar anchoring means in boreholes, especially in hollow checker firebrick, which is composed of a reactive resin, a curing agent component, as well as a foaming agent.
Abstract: A foamable, 2-component mortar composition is used to fix tie bars and similar anchoring means in boreholes, especially in hollow checker firebrick. The mortar composition is composed of a reactive resin, a curing agent component, as well as a foaming agent. The volume of the mortar composition required for the anchoring can be reduced significantly with the inventive composition. This is particularly important for anchorings which cross hollow checker firebrick.
31 citations
TL;DR: In this article, a continuum damage model for cement paste and mortar is presented, and the limitations and possible extensions of these models when applied to concrete are also presented, to facilitate model implementation, a simple and efficient computational update procedure for damage variable is also considered.
Abstract: Continuum damage models are presented within the framework of elastic‐damage theory for cement paste and mortar. Basic elements of continuum damage mechanics are given, and various types of extensions of elastic‐damage models are proposed. The limitations and possible extensions of these models when applied to concrete are also presented. To facilitate model implementation, a simple and efficient computational update procedure for damage variable is also considered. To assess the applicability of the damage models proposed, well‐documented experimental programs are performed through the use of a data acquisition system developed in the University of California, Berkeley. In particular, through the use of a systematic parameter estimation algorithm, the effects of porosity and sand concentration on the initiation and growth of microcracks are clearly demonstrated.
31 citations
TL;DR: In this article, an experimental study on the corrosion resistance of steel fibres and steel bar reinforcement in cement mortar was presented. But the results showed that the addition of calcium chloride modified the microstructure of the mortar matrix, both its water absorption capacity and its porosity increased with increasing amounts ofcium chloride.
TL;DR: The results of a systematic investigation on the effects of percolation by solutions of magnesium sulphate and magnesium chloride of the same normality, respectively, through mortar samples manufactured with different types of cement is given by the authors as mentioned in this paper.
Patent•
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27 Feb 1989
TL;DR: A horizontally oriented mortar mixing drum fabricated of polyethylene material having an elemental cylindrical segment opening through which mortar materials to be mixed may be deposited into or poured from a perimeter frame having base elemental frame member 15, diametric wall frame members 16 and polyethylenes grate 20 is provided for enhancing resistance to torsional stress on drum 11 Wear resistant liner 12 and side panels 13 and 14 cover the interior surface of drum 11 Paddle shaft 18 is rotatably and axially supported within drum 11 and has paddle stubs 28 attached to and extending radially therefrom Polyethyl
Abstract: A horizontally oriented mortar mixing drum 11 fabricated of polyethylene material having an elemental cylindrical segment opening through which mortar materials to be mixed may be deposited into or poured from A perimeter frame having base elemental frame member 15, diametric wall frame members 16 and polyethylene grate 20 is provided for enhancing resistance to torsional stress on drum 11 Wear resistant liner 12 and side panels 13 and 14 cover the interior surface of drum 11 Paddle shaft 18 is rotatably and axially supported within drum 11 and has paddle stubs 28 attached to and extending radially therefrom Polyethylene mixing paddles 19 are sleeved onto paddle stubs 28 to complete improved mortar mixing drum assembly 10
TL;DR: In this article, Mortar specimens were made using a total of five kinds of ordinary portland cement including two of different Na 2 O-equivalent alkali content (R 2 O) and three kinds of varying R 2 O to a maximum of 1.5% through addition of NaOH, and accelerated carbonation tests were performed.
TL;DR: In this article, an experimental investigation into the pore structure of hardened cement paste and mortar was performed using a mercury porosimeter, which was found to flatten out as the fine aggregate content increased.
DOI•
01 May 1989
TL;DR: In this paper, the effect of fly ash on the temperature rise of mortars included the use of both ASTM C 618 Class C and Class F fly ashes, while partial replacement of cement with Class C fly ash did not lower the mortar temperature, regardless of the type of cement used.
Abstract: This paper describes how a research program was conducted in which the temperature rise of mortars and the durability of concrete containing fly ash were studied. The study of the effect of fly ash on the temperature rise of mortars included the use of both ASTM C 618 Class C and Class F fly ashes. Control tests were conducted on mortars containing ASTM C 150 Type I, Type I-II, and Type III cements, and comparison tests were conducted on mortars containing 20, 27.5, and 35 percent fly ash by volume of cement. It was found that the use of Class F fly ash resulted in a reduction in the temperature of the mortar, whereas the partial replacement of cement with Class C fly ash did not lower the mortar temperature, regardless of the type of cement used. Resistance to scaling in the presence of deicing salts and abrasion resistance tests were conducted on concrete samples cast from 21 batches of concrete. Variables studied included fly ash type, fly ash content, and curing conditions. Both ASTM Class F and Class C fly ashes were used to replace 25 or 35 percent of the cement by volume, and curing conditions included combinations of 50, 75, and 100 F with 50 and 100 percent relative humidities.
01 Jan 1989
TL;DR: In this paper, the activation of granulated blast furnace slag (GBFS) and slag fly ash/burn clay pozzolana mixes in presence of lime and lime with gypsum is discussed.
Abstract: This paper deals with the activation of granulated blast furnace slag (GBFS) and slag-fly ash/burn clay pozzolana mixes in presence of lime and lime with gypsum. The paper highlights the effectiveness of lime- GBFS mix with and without additives as an alternative binding material. It includes mortar studies and stabilisation of alluvial soil with lime-GBFS mixes. Investigations showed that strength development of 1:3 mortar was highest when 7.5 per cent gypsum was also added to lime-GBFS mix. The alluvial soils could be satisfactorily stabilised with both lime-GBFS and lime-GBFS with 7.5 per cent gypsum or by replacing 20 per cent of GBFS with fly ash. (A)
TL;DR: In this article, experiments were carried out in PMMA with similar geometry to that used by Bazant and Pfeiffer and a numerical simulation was made assuming Mode I crack growth.
Abstract: Experiments by Bazant and Pfeiffer on concrete and mortar seem to indicate that crack growth does not necessarily take place under Mode I conditions. In order to investigate the influence of the material, experiments were carried out in PMMA with similar geometry to that used by Bazant and Pfeiffer and a numerical simulation was made assuming Mode I crack growth. The experimental results for PMMA differ significantly from those in concrete and mortar, but agree closely with the result from the numerical simulations. The difference is believed to be explained by the fact that small-scale yielding conditions are not realized well enough in concrete and mortar. A fairly large region of small cracks probably influences the crack growth direction.
Patent•
05 May 1989TL;DR: In this article, a reinforcing apparatus (8) is fitted in each n-th bed joint and the horizontal reinforement of the reinforcing apparatus is embedded in a mortar layer (20) of the bed joint.
Abstract: A reinforcing apparatus (8) is fitted in each n-th bed joint (4). The horizontal reinforement (10) of the reinforcing apparatus is embedded in a mortar layer (20) of the bed joint (4). Vertical reinforcing elements (16, 18) of adjacent reinforcing apparatuses (8) are arranged two by two in the vertical recesses (22) of the building stones (2) overlapping each other at least in part and embedded in a mortar mass (26). This way, a horizontally and vertically reinforced masonry wall is obtained, which can be constructed in practice in accordance with the usual method of construction.
Patent•
01 Sep 1989
TL;DR: Disclosed as discussed by the authors is a method of improving the quality of a structure to be prepared from mortar or concrete, the method being characterized in that when the mortar orcrete is kneaded, a water-soluble amino resin is admixed therewith, or a water solubile amino resin and at least one of a higher fatty acid metal salt and a nonionic surfactant are mixed therewith.
Abstract: Disclosed is a method of improving the quality of a structure to be prepared from mortar or concrete, the method being characterized in that when the mortar or concrete is kneaded, a water-soluble amino resin is admixed therewith, or a water-soluble amino resin and at least one of a higher fatty acid metal salt and a nonionic surfactant are admixed therewith.
TL;DR: In this article, a model for cement mortars under sulfate attack is proposed based on a progressive fracturing concept, where the initial damage of a mortar is defined as a function of the Powers' gel space ratio.
Abstract: A model for cement mortars under sulfate attack is proposed based on a progressive fracturing concept. An initial damage of mortar is defined as a function of the Powers' gel space ratio. The sulfate attack evidenced by the expansion of the matrix is incorporated as additional nucleated voids which increase the initial damage existing before the loading. The compressive properties of cement mortars under sulfate attack are predicted well by this model. Expansion limits for sulfate attack computed by this model agree well with those proposed by Mather and Patzias.
01 Jan 1989
DOI•
01 May 1989
TL;DR: In this article, the effect of finely ground silica with a high specific surface of about 12 m²/g and 20 mµ/g in mortar was compared with that containing silica fume.
Abstract: This paper will discuss the effect of finely ground silica with a high specific surface of about 12 m²/g and 20 m²/g in mortar and was compared with that containing silica fume. The dosage requirement of a high-range water-reducing agent to maintain a constant flow of fresh mortar was determined for 1:3 mortar containing 5 to 25 percent finely ground silica or silica fume as cement replacement. The compressive and flexural strengths of the mortar were investigated at different ages. Also, the resistance of mortar specimens to chemical attack and chloride penetration was determined. It was concluded that the use of finely ground silica was as effective as silica fume for improving quality of mortar.
TL;DR: In this paper, the authors used the physical and geometric properties of mortar and concrete brick elements to predict the behavior and ultimate strength of brick or concrete block masonry prisms or assemblage.
Abstract: Using the physical and geometric properties of mortar and concrete brick (or block) elements, and attempt is made to predict the behavior and ultimate strength of brick or concrete block masonry prisms or assemblage. The loading curve for a given strength mortar is obtained from experimentally measured stress-strain data. Failure envelopes were established for the mortar following Mohr's theory of failure line, and for the block from the results of numerical analysis of solid masonry prisms. The proposed failure envelopes for predicting ultimate strength of masonry prisms showed good agreement with available experimental data.
Patent•
25 Jul 1989
TL;DR: In this article, an adjustable apparatus for spreading mortar onto bricks or blocks is described, which utilizes augers and is readily adjusted to extrude beads of mortar onto the proper portions of bricks/blocks having different widths.
Abstract: This invention discloses an adjustable apparatus for spreading mortar onto bricks or blocks. The apparatus utilizes augers and is readily adjusted to extrude beads of mortar onto the proper portions of bricks/blocks having different widths. A trowel member is provided on the extrusion ports to smooth the beads of mortar. The apparatus includes a lid member that contains water for wetting the mortar. The weight of the lid member containing water also helps urge the mortar out of the hopper through the extrusion ports. Mortar gate plate members to regulate flow of mortar through the extrusion ports are also provided.
Patent•
25 Jan 1989
TL;DR: In this paper, a mixture of plaster and mortar is mixed with a pore-former and the mixture is moved by a stirrer on a free surface in contact with the air.
Abstract: of EP0300342The device for mixing plaster or mortar has, in succession, a mortar container (14), a mixer (15), a pump (12) and a conveying hose, and a vessel (10) provided with a stirrer (21, 23) is connected between the mixer (15) and the pump (12), the mixture having a free surface (37) in contact with the air and moved by the stirrer (21, 23). This enables the air content of the mortar/water mixture to be better controlled. Via the free surface in contact with the air, the same mortar/water mixture, provided with surface-active agents as pore formers, receives far more finely distributed air than is possible with conventional types of air introduction. For this purpose, the stirrer does not even need to strike the air. It can remain below the surface and needs only to generate movement on the surface. By contrast, the mortar, which is provided with anti-foaming agents, defoams on the free surface. The majority of the unwanted air escapes.
Patent•
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04 Oct 1989
TL;DR: In this paper, a dry mortar mix based on an inorganic bonding agent and optionally additives, plastics, fibres, and other conventional concrete additives is proposed especially to protect concrete structures and/or to eliminate surface damage to such structures.
Abstract: A dry mortar mix based on an inorganic bonding agent and optionally additives, plastics, fibres, and other conventional concrete additives is proposed especially to protect concrete structures and/or to eliminate surface damage to such structures In addition to the inorganic bonding agent, the dry mortar mix contains a granular additive to increase alkalinity, this having a reaction speed that is a considerably lower than that of the granular bonding agent This "reserve alkalinity" serves to counteract the diffusion of CO 2 and SO 2 from the air into the concrete, and the damage to the concrete that is attendant on such diffusion
Patent•
30 Jun 1989
TL;DR: In this paper, the authors proposed a method to eliminate manual work and carry out an efficient construction project by shifting a mortar applying and leveling device on the surface of a building from upper to lower sides while discharging mortar by means of the mortar applying device having a trowel provided beneath its mortar discharge opening.
Abstract: PURPOSE: To eliminate manual work and carry out an efficient construction project by shifting a mortar applying and leveling device on the surface of a building from upper to lower sides while discharging mortar by means of the mortar applying device having a trowel provided beneath its mortar discharge opening, and rolling and applying the mortar by means of the trowel CONSTITUTION: A mortar applying and leveling device 3 is provided between the surface of a building 1 and a scaffold in such a manner as being separate from and parallel to the surface and the scaffold, and are shifted along lower rails 4, 4 and also a main body frame 6 is formed which can be fixed in a desired position A horizontally moving member 20 which moves horizontally along the rails 4 and a vertically moving member 24 which moves vertically, are provided A bracket 26 which moves vertically, and a mortar discharge opening 34 mounted to the bracket, and a mortar applying device 31 provided with a trowel 35 beneath the discharge opening, are formed The mortar discharge opening 34 is connected to a mortar supply device 37 via a mortar pressure feed pipe 36 so that while mortar is discharged it is applied by the trowel 35 COPYRIGHT: (C)1991,JPO&Japio