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Showing papers on "Screed published in 2021"


Journal ArticleDOI
TL;DR: In this paper, the thermal impact of using lightweight concrete in Lebanese building constructions was assessed by pouring an 8 cm thickness of lightweight concrete on the roof and the slab and replacing traditional hollow concrete block by lightweight concrete blocks.
Abstract: Innovative building materials are being used in building envelopes for reducing their heating and cooling needs. This paper aims to assess the thermal impact of using lightweight concrete in Lebanese building constructions by pouring an 8 cm thickness of lightweight concrete on the roof and the slab and replacing traditional hollow concrete block by lightweight concrete blocks. Thermal properties of two different samples were experimentally determined: the first one (558 kg/m3) used for the roof and the slab and the second one (1074 kg/m3) used for the walls. Then numerical simulations were carried out for a Lebanese traditional detached house using the characteristics of these two samples. The thermally improved Light Weight Concrete building (LWC) was compared to a traditional Lebanese house base case (BC) using a dynamic building energy simulation tool in the four different Lebanese climate zones: coastal, mid-mountain, mountain, and inland zones. The results highlight the effectiveness of integrating LWC to building envelopes by reducing energy consumption and improving thermal comfort in both winter and summer climate conditions and in the different Lebanese climatic zones. The paper demonstrates that the use of LWC in the vertical walls replacing the traditional hollow blocks can reduce the heating needs by up to 9% and by up to 13% for cooling needs. On the other hand, adding a LWC roof screed has a very high impact on cooling and heating energy consumption, which can reach up to 74% in cooling energy savings and up to 24% in heating energy savings.

14 citations


Journal ArticleDOI
TL;DR: A method to evaluate the pre-compaction of bulk materials via the average aggregate angular velocity was proposed in this study and validated through the test track, and the index Compaction Increase Ratio (CIR) was defined to compare and describe the quality of pre-Compaction.

10 citations


Journal ArticleDOI
TL;DR: In this paper, the optimal thickness of aluminum radiant sheet in the lightweight floor heating, i.e., the smallest thickness of the aluminium, ensuring high efficiency and thermal comfort, is determined.
Abstract: The aim of this work is to determine the optimal thickness of aluminium radiant sheet in the lightweight floor heating, i.e. the smallest thickness of the aluminium, ensuring high efficiency and thermal comfort. The optimal operational and construction parameters are determined regards to the aluminium thickness. Finding the optimal aluminium thickness is important for economic and ecological reasons: less aluminium thickness, less aluminium consumption and less cost of construction. Numerical calculations were performed with ANSYS Steady-State Thermal Solver (Workbench 19.2) for floor heating with a dry screed, wood-like board and pipes embedded in the layer of tile adhesive. The influence of aluminium thickness changes in the range of 0.1–0.5 mm was analysed for variable water temperature, pipe spacing and constructions. The optimal aluminium radiant sheet thickness is 0.3 mm, 0.1 mm is not recommended. The optimal water temperature is 25–35 °C, 45 °C is not recommended. Constructions with a dry screed 25 mm thick should not be used. Constructions with pipes in tile adhesive should be used at a water temperature of 25–30 °C and an aluminium thickness of 0.3–0.5 mm. Constructions with wood-like board should be used at a water temperature of 25–35 °C and an aluminium of 0.3–0.4 mm. Results enable a conscious choice of such constructions and operational parameters of lightweight floor heating that ensure high efficiency, thermal comfort and low investment costs. The work includes the original specification of the lightweight floor heating efficiency depending on the radiant sheet thickness and specifies recommended radiant sheet thicknesses.

10 citations


Journal ArticleDOI
TL;DR: In this article, the structural members of a seven-story building from the end of the 18th century were evaluated following a procedure based on previous research works, which is explained by floor screed stiffness, the transverse stiffness effect and possible semi-rigid connection behaviour at the supports.

6 citations


Journal ArticleDOI
TL;DR: In this paper, a nonlinear dynamic vibration system of the interaction between asphalt mixture and screed plate was proposed to improve the paving density of asphalt pavement, and the results indicated that the optimal vibration frequency was higher than the natural frequency and further compaction with a lower vibration frequency can effectively improve the energy absorption efficiency.

5 citations


Journal ArticleDOI
TL;DR: In this article, a structural lightweight concrete with an ultra-high-performance matrix and expanded glass as a lightweight aggregate was examined from the aspect of durability, and the results showed that most of the measured capillary pores resulted from the lightweight aggregate and were not all present as a pore system.
Abstract: It is important to ensure the durability and safety of structures. In the case of newly developed materials that are outside the current rules, it is important to investigate all aspects of structural safety. The material studied in the following is a structural lightweight concrete with an ultra-high-performance matrix and expanded glass as a lightweight aggregate. The material, with a compressive strength of 60–100 MPa and a bulk density of 1.5–1.9 kg/dm3, showed high capillary porosities of 12 vol% (ultra-high-performance concretes (UHPC) < 5 vol%). Since the capillary porosity basically enables transport processes into the concrete, the material had to be examined more closely from the aspect of durability. Freeze-thaw resistance (68 g/m2) and chemical attack with sulfate at pH 3.5 for 12 weeks (16 g/m2) showed no increase in concrete corrosion. Targeted carbonation (0.53 mm/year0.5) and chloride penetration resistance (6.0 × 10−13 to 12.6 × 10−13 m2/s) also showed good results against reinforcement corrosion. The results show that most of the measured capillary pores resulted from the lightweight aggregate and were not all present as a pore system. Thus, the durability was only slightly affected and the concrete can be compared to an UHPC. Only the abrasion resistance showed an increased value (22,000 mm3/5000 mm2), which, however, only matters if the material is used as a screed.

4 citations


Journal ArticleDOI
TL;DR: In this article, the influence of moisture damage on ground-penetrating radar (GPR) signals at different floor constructions was studied. And the obtained data set was then used to investigate suitable signal features to classify three scenarios: dry, damaged insulation, and damaged screed.
Abstract: To date, the destructive extraction and analysis of drilling cores is the main possibility to obtain depth information about damaging water ingress in building floors. The time- and cost-intensive procedure constitutes an additional burden for building insurances that already list piped water damage as their largest item. With its high sensitivity for water, a ground-penetrating radar (GPR) could provide important support to approach this problem in a non-destructive way. In this research, we study the influence of moisture damage on GPR signals at different floor constructions. For this purpose, a modular specimen with interchangeable layers is developed to vary the screed and insulation material, as well as the respective layer thickness. The obtained data set is then used to investigate suitable signal features to classify three scenarios: dry, damaged insulation, and damaged screed. It was found that analyzing statistical distributions of A-scan features inside one B-scan allows for accurate classification on unknown floor constructions. Combining the features with multivariate data analysis and machine learning was the key to achieve satisfying results. The developed method provides a basis for upcoming validations on real damage cases.

4 citations


Journal ArticleDOI
01 Feb 2021
TL;DR: The test results show that the test bench measurement and control software based on LabVIEW has perfect functions and meets the requirements of screed test.
Abstract: In order to meet the requirements of the performance test of the screed, a hydraulic test bench for screed is designed, which realizes the action of the screed. On this basis, the test bench measurement and control software based on LabVIEW is developed, it completes the tests and data analysis of screed. The test results show that the system has perfect functions and meets the requirements of screed test.

2 citations


Journal ArticleDOI
TL;DR: A simplified model using the linearization of the Cremer-Ver relation is introduced, which can be applied to determine the probability density of sound insulation improvement for floating floor composed of XPS and cement screed in a simple and efficient way.

2 citations


Journal ArticleDOI
TL;DR: In this paper, the authors focused on the utilization of cable waste originating during the recycling of wires as a partial substitution of natural aggregate in cement screed and found an optimal level of substitution in terms of freezing-thawing resistance, which is a significant aspect for such type of concrete mixtures.
Abstract: This research is focused on the utilization of cable waste originating during the recycling of wires as a partial substitution of natural aggregate in cement screed. The main goal of the work performed was to find an optimal level of substitution in terms of freezing–thawing resistance, which is a significant aspect for such type of concrete mixtures. The studied artificial aggregate was gradually dosed in cement screed by 5% in a volume of up to 30% of substitution. The influence of the substitution was also evaluated in terms of compressive strength, flexural strength, bulk density determination, and the ultrasonic pulse method. Gradual substitution led to the reduction of the bulk density and studied mechanical properties due to the considerable air-entraining effect. The utilization of cable waste reduced the value of modulus of elasticity and modified deformation behavior of studied mixtures, which exhibited significant softening during the flexural test. Studied screed mixtures incorporating waste material exhibited slightly lower values of the coefficient of freeze-thaw resistance in comparison with the control mixture, however, the attained values comply with technical requirements.

1 citations


Patent
13 Jan 2021
TL;DR: In this paper, an accessory for levelling uncured concrete surfaces is described, which includes a screed head with two height adjusting levelling cylinders (1), a slope cylinder (2), a coupling component (3), a blade (4), an auger (5), a roller (6), a vibrator (7), and a sprinkler system (8).
Abstract: An accessory for levelling uncured concrete surfaces. The accessory includes a screed head with two height adjusting levelling cylinders (1), a slope cylinder (2), a coupling component (3), a blade (4), an auger (5), a roller (6), a vibrator (7) and a sprinkler system (8). The coupling component (3) includes a hand operated hinged latch with a hook able to be snapped in place in a single movement so as to pinch together the coupling component and a telescopic boom of a general-purpose vehicle. The slope cylinder (2) enables the screed head to be maintained continuously at ninety degrees to the horizontal.

Patent
Schuette Ryan J1
13 May 2021
TL;DR: In this article, a method for cleaning a screed of a paving machine includes activating a vibration generator to induce a vibration into the screed such that screed is excited at a resonant frequency of screed to cause dislodgement of a residual build-up of a material from the material.
Abstract: A method for cleaning a screed of a paving machine includes activating a vibration generator to induce a vibration into the screed such that the screed is excited at a resonant frequency of the screed to cause dislodgement of a residual build-up of a material from the screed.

Patent
27 May 2021
TL;DR: A screed plug for placement in an open end of a conduit comprises: a first surface, a second surface, and at least one side wall extending between the first surface and the second surface; a recess formed in the firstsurface; and a handle for manipulating the screedplug as discussed by the authors.
Abstract: A screed plug for placement in an open end of a conduit comprises: a first surface; a second surface; and at least one side wall extending between the first surface and the second surface; a recess formed in the first surface; and a handle for manipulating the screed plug. The handle is movable from at least a first position within the recess and a second position projecting from the recess.



Book ChapterDOI
01 Jan 2021
TL;DR: In this paper, the flexural behavior of precast prestressed HCS made of Styrofoam, with 10 m span, was examined experimentally, and two specimens were tested, one with screed (topping) concrete and other without screed concrete.
Abstract: In general, the total cost of the building is mainly influenced by the self-weight of structural members. In particular, the self-weight of the floor slab is a key parameter which restricts its span. The hollow core slab (HCS) is being developed as an alternate to the conventional solid slab and results in self-weight reduction up to 50%. However, the reduction in the cross-sectional area increases the flexural deflection, which can be overcome by prestress technology. In this study, the flexural behaviour of precast prestressed HCS made of Styrofoam, with 10 m span, was examined experimentally. Two specimens were tested, one with screed (topping) concrete and other without screed concrete. The influence of screed concrete on the flexural and creep behaviour was investigated. It is found that the screed concrete reduces the flexural and creep deflection significantly. The applicability of HCS system to industrial buildings was investigated by adopting a service load as per Indian standard, IS 875 (Part 2): 1987, and subsequently found that the HCS satisfies the code requirements related to strength and serviceability (deflection and crack). Additionally, it was observed that the voids significantly influences the shear capacity of precast prestressed HCS.

Patent
27 Jan 2021
TL;DR: In this article, a road finisher with a paving screed and a traction arm is described, where a pedestrian plate is arranged at the rear end of the screed, at least one railing module is attached to the pedestrian plate, and a storage device is used for accommodating objects.
Abstract: The invention relates to a road finisher (1) having a tractor (2) with a paving screed (4) connected to the tractor (2) by a traction arm (3) and transversely aligned with a direction of travel (F). Ascreed pedestrian plate (5) is arranged at the rear end of the paving screed (4), at least one railing module (6) is attached to the screed pedestrian plate (5), and at least one storage device (7) used for accommodating objects is attached to the railing module (6).

Patent
29 Apr 2021
TL;DR: In this article, an adjustable screed assembly suitable for mounting to a paver is presented, where the screed plate is moveable relative to the mounting member along the direction from the first end to the second end.
Abstract: There is provided an adjustable screed assembly suitable for mounting to a frame of a paver, the screed assembly comprising a mounting member, the mounting member having a first end and a second end, the mounting member including at least one elongate aperture passing through the mounting member and extending along the mounting member in a direction from the first end to the second end, the mounting member being pivotally connected to the frame at or proximate to the first end and being slidingly connected to a screed arm through the at least one elongate aperture, wherein the screed plate is moveable relative to the mounting member along the direction from the first end to the second end.



Patent
05 May 2021
TL;DR: In this article, a paving screed for compacting a paving material, comprising at least one external control station for an operator for controlling at least 1 operating parameter adjustable on the screed, for example, the power of a screed heating system.
Abstract: The present disclosure refers to a paving screed for compacting a paving material, comprising at least one external control station for an operator for controlling at least one operating parameter adjustable on the screed, for example a power of a screed heating system. The external control station comprises a support and at least one operating panel detachably attached thereto as an input unit for the operator for setting the at least one operating parameter. The operating panel is attached to the support by means of a plug connection device having a first plug connector part with at least one first electrical contact part integrated thereon and a second plug connector part with at least one second electrical contact part integrated thereon. Furthermore, an electrical coupling of the two electrical contact parts integrated on the plug connector parts can be produced by a mechanical coupling of the two plug connector parts.

Patent
14 Apr 2021
TL;DR: In this article, a mixture of asphalt, bitumen, and aggregate is mixed using a single movable machine, the front being the motion of the machine moving forwardly F. The screed spreads and tamps the mixture on the road surface.
Abstract: The apparatus comprises: a heater array, 1, 2, 3, 4; a mixer 26 and a screed 22. The heater, mixer and screed are arranged linearly from front to back onto a single movable machine, the front being the motion of the machine moving forwardly F. The heater is for heating asphalt wearing courses on both sides of a joint. The mixer can deposit heated bitumen and has agitators for disturbing the heated asphalt and then mixing the asphalt, bitumen to create a mixture and aggregate. The screed spreads and tamps the mixture on the road surface. Also claimed is a method including the successive steps of: a) heating a surface of asphalt wearing courses; b) spraying heated bitumen onto the surface; c) agitating the asphalt and partially mixing the bitumen; d) adding aggregate onto the disturbed asphalt and bitumen; e) agitating teh asphalt, bitumen and aggregate and mixing them together and f) spreading the tamping the mixture on either side of the surface of the joint.

Patent
17 Jun 2021
TL;DR: A paving machine can include a frame; a screed coupled to the frame; and a density sensor coupled to a paving machine and configured to measure a density of an asphalt mat as the screed passes over the asphalt mat as mentioned in this paper.
Abstract: A paving machine can include a frame; a screed coupled to the frame; and a density sensor coupled to the paving machine and configured to measure a density of an asphalt mat as the screed passes over the asphalt mat.

Patent
27 Jan 2021
TL;DR: In this paper, a method of using the screed composition is provided comprising mixing the cement, additives, EPS beads and water at or adjacent a point of use and applying the mixed screed mixture to a surface to be coated at said point-of-use.
Abstract: A screed composition comprising: cement; additives including at least a surfactant and a foaming agent; expanded polystyrene beads; and water. The additives may further comprise an accelerator. The screed composition may have a density of between 80 and 300 kg/m3. The EPS beads may have a size of between 1 and 8 mm and a density of between 8 and 16 kg/m3. A method of using the screed composition is provided comprising mixing the cement, additives, EPS beads and water at or adjacent a point of use and applying the mixed screed composition to a surface to be coated at said point of use. The method may comprise: adding the additives to at least a portion of the water in a mixing device; adding the EPS beads to the water and additives in the mixing device and mixing for a period; adding the cement to the mixing device and mixing for a further period. The surface to be coated may be a subfloor. At least the cement, water and EPS beads may be separate from one another prior to mixing at or adjacent the point of use.

Patent
09 Jun 2021
TL;DR: In this article, a concrete subfloor is constructed using expanded polystyrene (EPS) beads and additives including a surfactant and a foaming agent, and a hard finish top coating or surface screed is applied over the screed.
Abstract: The building structure comprises a concrete subfloor 10, external cavity walls 2 with skins 4,6 separated by a cavity containing bead insulation 8 extending below or adjacent to the subfloor, and a screed layer 14 on the subfloor. The floor screed comprises cement, expanded polystyrene (EPS) beads, and additives including a surfactant and a foaming agent. The wall skins may comprise concrete blocks. Adjacent to the screed and optionally also the subfloor, the blocks forming the inner skin may be thermally insulated blocks 12, e.g. incorporating polystyrene beads and additives including a surfactant and a foaming agent. A hard finish top coating or surface screed 16, optionally with a vapour barrier 18 (e.g. polythene sheet) beneath it, may be applied over the screed. Polythene foam strips 20 may be used as perimeter insulation between the top coating and exterior walls. The structure may have linear thermal transmittance of 0.127 W/mK and temperature factor for humidity and mould of 0.877. Also claimed is a method of constructing a building structure.

Patent
19 Jan 2021
TL;DR: In this article, a screed head assembly is movable over the concrete surface via the screeding machine and a control uses gyroscope sensor data and angle sensor data to determine pitch angle and/or roll angle.
Abstract: A screeding machine for screeding an uncured concrete surface includes a screed head assembly movable over the concrete surface via the screeding machine. A pair of elevation sensors disposed at opposite ends of the screed head assembly sense an elevation of the respective end of the screed head assembly. An angle sensor disposed at the screed head assembly senses a pitch angle and/or a roll angle of the screed head assembly. A gyroscope sensor disposed at the screed head assembly senses rotational velocity of the screed head assembly about a lateral axis and/or a longitudinal axis of the screed head assembly. A control uses gyroscope sensor data and angle sensor data to determine pitch angle and/or roll angle of the screed head assembly. The control controls the screed head assembly based on the signals from one or both of the elevation sensors and the determined pitch and/or roll angles.