GUNITECH®: An Innovative Pumice Based Dry Shotcrete Application

2021 ◽  
Vol 5 (1) ◽  
pp. 46
Author(s):  
Maria Nomikou ◽  
Vasileios Kaloidas ◽  
Christos Triantafyllos Galmpenis ◽  
Nicolaos Anagnostopoulos ◽  
Georgios Tzouvalas
Keyword(s):  
Soil Stabilization ◽  
Lightweight Concrete ◽  
Lightweight Aggregate ◽  
New Product ◽  
Low Density ◽  
Brand Name ◽  
Masonry Unit ◽  
Foreign Markets ◽  
Pumice Stone ◽  
Loose Soil

Pumice quarried by LAVA MINING AND QUARRYING SA from Yali Island, Dodecanese, is used in domestic and foreign markets mainly as concrete lightweight aggregate, masonry unit constituents, road substrate, and loose soil stabilization. It is a porous natural volcanic rock with low density, low thermal and noise transmission, and the highest strength among all the natural or artificial lightweight materials of mineral origin. Nowadays, pumice is of additional interest as it has a reduced CO2 footprint because thermal energy is not needed for its expansion compared with the artificial lightweight aggregates. In this context, HERACLES GROUP in collaboration with Sika Hellas has launched a new product containing pumice stone under the brand name GUNITECH®. GUNITECH® is an innovative bagged material for spraying concrete applications. It is a ready lightweight concrete, for building repairs certified as EN 1504-3.

scholarly journals Using Attapulgite as a Lightweight Aggregate to Produce Structural and Insulating Concrete

2019 ◽  
Vol 26 (2) ◽  
pp. 131-139
Author(s):  
Hind Hussein Hammad ◽  
Zeyad Momtaz Mohamed ◽  
Tmara Rasheed
Keyword(s):  
Thermal Insulation ◽  
Lightweight Concrete ◽  
Low Cost ◽  
Construction Materials ◽  
Lightweight Aggregate ◽  
Economic Feasibility ◽  
Lightweight Aggregate Concrete ◽  
Fine Aggregate ◽  
Low Density ◽  
Aggregate Concrete

The wide spread of lightweight concrete due to its properties like low density, good thermal insulation, and the economic feasibility of low cost for buildings constructed with this type of concrete. The studies in this field of construction materials have varied, in this research, one types of the lightweight concrete was produced. It is a lightweight aggregate concrete. Crushed attapulgite rocks was used as aggregate which fired at temperature of 700°C and used as partially or completely replacement with ordinary aggregates to production low-density concrete blocks both structural and insulating, The properties of the concrete produced which tested for (density, compressive strength, thermal conductivity, linear  shrinkage, splitting  strength) is conformed to the requirements of international specifications, the mix (GP) which contain 50% fine attapulgite aggregate and 50% ordinary fine aggregate with 100% coarse attapulgite aggregate conforms to the properties of structural lightweight concrete  according to ASTM C330 and its gave a density about 1668Kg/m3 and compression strength of 17.5 N/mm2, while the two mixtures (H, HP) consisting of fine and coarse attapulgite aggregate with 100% of the total aggregate in mixture, with weight of 10% from cement as a pozzolana material in the mix HP is identical to the properties of the insulating lightweight aggregate concrete according to ASTM C332 with density about (1380,1432)Kg/m3 and thermal insulation   (0.37,0.41)w/mk°, respectively.

scholarly journals Effects of carbon nanotubes on expanded glass and silica aerogel based lightweight concrete

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Suman Kumar Adhikary ◽  
Žymantas Rudžionis ◽  
Simona Tučkutė ◽  
Deepankar Kumar Ashish
Keyword(s):  
Carbon Nanotubes ◽  
Compressive Strength ◽  
Silica Aerogel ◽  
Lightweight Concrete ◽  
Lightweight Aggregate ◽  
Cementitious Materials ◽  
Lightweight Aggregate Concrete ◽  
Multi Wall Carbon Nanotubes ◽  
Sem Image ◽  
Study Results

AbstractThis study is aimed to investigate the effect of carbon nanotubes on the properties of lightweight aggregate concrete containing expanded glass and silica aerogel. Combinations of expanded glass (55%) and hydrophobic silica aerogel particles (45%) were used as lightweight aggregates. Carbon nanotubes were sonicated in the water with polycarboxylate superplasticizer by ultrasonication energy for 3 min. Study results show that incorporating multi-wall carbon nanotubes significantly influences the compressive strength and microstructural performance of aerogel based lightweight concrete. The addition of carbon nanotubes gained almost 41% improvement in compressive strength. SEM image of lightweight concrete shows a homogeneous dispersal of carbon nanotubes within the concrete structure. SEM image of the composite shows presence of C–S–H gel surrounding the carbon nanotubes, which confirms the cites of nanotubes for the higher growth of C–S–H gel. Besides, agglomeration of carbon nanotubes and the presence of ettringites was observed in the transition zone between the silica aerogel and cementitious materials. Additionally, flowability, water absorption, microscopy, X-ray powder diffraction, and semi-adiabatic calorimetry results were analyzed in this study.

scholarly journals Influence of Lightweight Aggregate Concrete Materials on Building Energy Performance

Buildings ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 94
Author(s):  
Tara L. Cavalline ◽  
Jorge Gallegos ◽  
Reid W. Castrodale ◽  
Charles Freeman ◽  
Jerry Liner ◽  
...  
Keyword(s):  
Thermal Properties ◽  
Building Materials ◽  
Energy Savings ◽  
Lightweight Concrete ◽  
Lightweight Aggregate ◽  
Building Energy ◽  
Energy Performance ◽  
Energy Simulation ◽  
Building Energy Simulation ◽  
Building Energy Performance

Due to their porous nature, lightweight aggregates have been shown to exhibit thermal properties that are advantageous when used in building materials such as lightweight concrete, grout, mortar, and concrete masonry units. Limited data exist on the thermal properties of materials that incorporate lightweight aggregate where the pore system has not been altered, and very few studies have been performed to quantify the building energy performance of structures constructed using lightweight building materials in commonly utilized structural and building envelope components. In this study, several lightweight concrete and masonry building materials were tested to determine the thermal properties of the bulk materials, providing more accurate inputs to building energy simulation than have previously been used. These properties were used in EnergyPlus building energy simulation models for several types of commercial structures for which materials containing lightweight aggregates are an alternative commonly considered for economic and aesthetic reasons. In a simple model, use of sand lightweight concrete resulted in prediction of 15–17% heating energy savings and 10% cooling energy savings, while use of all lightweight concrete resulted in prediction of approximately 35–40% heating energy savings and 30% cooling energy savings. In more complex EnergyPlus reference models, results indicated superior thermal performance of lightweight aggregate building materials in 48 of 50 building energy simulations. Predicted energy savings for the five models ranged from 0.2% to 6.4%.

Production of Low-Density Ceramics Using Pumice Stone

2004 ◽  
Vol 264-268 ◽  
pp. 2527-2530
Author(s):  
Ömer E. Kuzugüdenli ◽  
G. Zengin
Keyword(s):  
Low Density ◽  
Pumice Stone

Permeability of Lightweight Aggregate Concrete with Mineral Admixture

2013 ◽  
Vol 857 ◽  
pp. 105-109
Author(s):  
Xiu Hua Zheng ◽  
Shu Jie Song ◽  
Yong Quan Zhang
Keyword(s):  
Pore Structure ◽  
Lightweight Concrete ◽  
Chloride Ion ◽  
Lightweight Aggregate ◽  
Total Porosity ◽  
Normal Weight ◽  
Mineral Admixture ◽  
Mineral Admixtures ◽  
Lightweight Aggregate Concrete ◽  
Aggregate Concrete

This paper presents an experimental study on the permeability and the pore structure of lightweight concrete with fly ash, zeolite powder, or silica fume, in comparison to that of normal weight aggregate concrete. The results showed that the mineral admixtures can improve the anti-permeability performance of lightweight aggregate concrete, and mixed with compound mineral admixtures further more. The resistance to chloride-ion permeability of light weight concrete was higher than that of At the same strength grade, the anti-permeability performance of lightweight aggregate concrete is better than that of normal weight aggregate concrete. The anti-permeability performance of LC40 was similar to that of C60. Mineral admixtures can obviously improve the pore structure of lightweight aggregate concrete, the total porosity reduced while the pore size decreased.

scholarly journals Efficiency factor and modulus of elasticity of lightweight concrete with expanded clay aggregate

2010 ◽  
Vol 3 (2) ◽  
pp. 195-204 ◽  
Author(s):  
W.G Moravia ◽  
A. G. Gumieri ◽  
W. L. Vasconcelos
Keyword(s):  
Compressive Strength ◽  
Modulus Of Elasticity ◽  
Large Scale ◽  
Lightweight Concrete ◽  
Weight Ratio ◽  
Lightweight Aggregate ◽  
Normal Weight ◽  
Lightweight Aggregate Concrete ◽  
Empirical Methods ◽  
Normal Weight Concrete

Nowadays lightweight concrete is used on a large scale for structural purposes and to reduce the self-weight of structures. Specific grav- ity, compressive strength, strength/weight ratio and modulus of elasticity are important factors in the mechanical behavior of structures. This work studies these properties in lightweight aggregate concrete (LWAC) and normal-weight concrete (NWC), comparing them. Spe- cific gravity was evaluated in the fresh and hardened states. Four mixture proportions were adopted to evaluate compressive strength. For each proposed mixture proportion of the two concretes, cylindrical specimens were molded and tested at ages of 3, 7 and 28 days. The modulus of elasticity of the NWC and LWAC was analyzed by static, dynamic and empirical methods. The results show a larger strength/ weight ratio for LWAC, although this concrete presented lower compressive strength.

Lightweight Aggregate Concrete as an Alternative for Dense Concrete in Post-Tensioned Concrete Slab

2018 ◽  
Vol 926 ◽  
pp. 140-145 ◽  
Author(s):  
Małgorzata Mieszczak ◽  
Lucyna Domagała
Keyword(s):  
Mechanical Properties ◽  
Lightweight Concrete ◽  
Concrete Slab ◽  
Lightweight Aggregate ◽  
Lightweight Aggregate Concrete ◽  
Aggregate Concrete ◽  
Large Span ◽  
Shrinkage And Creep ◽  
Theoretical Results ◽  
Post Tensioned

The paper presents the results of tests conducted on two lightweight aggregate concretes made of new national Certyd artificial aggregate. This research is intended to first application of lightweight concrete to construct large-span post-tensioned slab. In addition to mechanical properties development, shrinkage and creep during 3 months of loading were tested. The obtained results are compared with theoretical results predicted by standard. Conducted tests indicated, that measured values of shrinkage and creep are significantly lower than predicted ones. This is promise for application of tested concrete in construction of post-tensioned slabs.

Evaluation of fire performance of lightweight concrete wall panels using finite element analysis

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Irindu Upasiri ◽  
Chaminda Konthesingha ◽  
Anura Nanayakkara ◽  
Keerthan Poologanathan ◽  
Brabha Nagaratnam ◽  
...  
Keyword(s):  
Finite Element ◽  
Lightweight Concrete ◽  
Lightweight Aggregate ◽  
Lightweight Aggregate Concrete ◽  
Fire Performance ◽  
Concrete Wall ◽  
Aggregate Concrete ◽  
Content Type ◽  
Wall Panels ◽  
Foamed Concrete

Purpose In this study, the insulation fire ratings of lightweight foamed concrete, autoclaved aerated concrete and lightweight aggregate concrete were investigated using finite element modelling. Design/methodology/approach Lightweight aggregate concrete containing various aggregate types, i.e. expanded slag, pumice, expanded clay and expanded shale were studied under standard fire and hydro–carbon fire situations using validated finite element models. Results were used to derive empirical equations for determining the insulation fire ratings of lightweight concrete wall panels. Findings It was observed that autoclaved aerated concrete and foamed lightweight concrete have better insulation fire ratings compared with lightweight aggregate concrete. Depending on the insulation fire rating requirement of 15%–30% of material saving could be achieved when lightweight aggregate concrete wall panels are replaced with the autoclaved aerated or foamed concrete wall panels. Lightweight aggregate concrete fire performance depends on the type of lightweight aggregate. Lightweight concrete with pumice aggregate showed better fire performance among the normal lightweight aggregate concretes. Material saving of 9%–14% could be obtained when pumice aggregate is used as the lightweight aggregate material. Hydrocarbon fire has shown aggressive effect during the first two hours of fire exposure; hence, wall panels with lesser thickness were adversely affected. Originality/value Finding of this study could be used to determine the optimum lightweight concrete wall type and the optimum thickness requirement of the wall panels for a required application.

scholarly journals The influence of OPC and PPC on compressive strength of ALWA concrete

2018 ◽  
Vol 195 ◽  
pp. 01021
Author(s):  
Fedya Diajeng Aryani ◽  
Tavio ◽  
I Gusti Putu Raka ◽  
Puryanto
Keyword(s):  
Compressive Strength ◽  
Coarse Aggregate ◽  
Lightweight Concrete ◽  
Lightweight Aggregate ◽  
Normal Weight ◽  
Structural Members ◽  
Concrete Composition ◽  
Normal Weight Concrete ◽  
To Come ◽  
Seismic Forces

Lightweight concrete is one of the options used in construction in lieu of the traditional normal-weight concrete. Due to its lightweight, it provides lighter structural members and thus, it reduces the total weight of the structures. The reduction in weight resulting in the reduction of the seismic forces since its density is less than 1840 kg/m3. Among all of the concrete constituents, coarse aggregate takes the highest portion of the concrete composition. To produce the lightweight characteristics, it requires innovation on the coarse aggregate to come up with low density of concrete. One possible way is to introduce the use of the artificial lightweight aggregate (ALWA). This study proposes the use of polystyrene as the main ingredient to form the ALWA. The ALWA concrete in the study also used two types of Portland cements, i.e. OPC and PPC. The ALWA introduced in the concrete comprises various percentages, namely 0%, 15%, 50%, and 100% replacement to the coarse aggregate by volume. From the results of the study, it can be found that the compressive strength and the modulus of elasticity of concrete decreased with the increase of the percentage of the ALWA used to replace the natural coarse aggregate.

Investigation on Improvement of Flexural Behavior of Low-Density Cellular Concrete through Fiber Reinforcement for Non-Structural Applications

2019 ◽  
Vol 2673 (10) ◽  
pp. 641-651
Author(s):  
Arman Abdigaliyev ◽  
Jiong Hu
Keyword(s):  
Mechanical Properties ◽  
Lightweight Concrete ◽  
Construction Material ◽  
Flexural Behavior ◽  
Unit Weight ◽  
Slight Reduction ◽  
Low Density ◽  
Hybrid Fibers ◽  
Structural Applications ◽  
Cellular Concrete

During the last decades, cellular lightweight concrete (CLC), or foamed concrete, has been experiencing greater interest in geotechnical, structural, and non-structural applications. The low density and high flowability makes it a favorable construction material in relation to handling, placing, and construction costs. However, the applications of low-density cellular concrete (LDCC), the category of CLC with a unit weight less than 50 pounds per cubic foot (801 kg/m3) and generally without fine aggregates, are limited mostly to backfill applications in geotechnical engineering. The main reason lies in the brittleness of the material and low to zero resistance to flexural loads. Fiber-reinforced LDCC may be a reasonable solution to improve mechanical properties and expand the application range of the material. This study investigated the effects of adding polypropylene and hybrid fibers on physical and mechanical properties of LDCC and the feasibility of expanding LDCC utilization to non-structural applications. Results showed that although there is a slight reduction of flowability and compressive strength, the flexural behavior of LDCC can be significantly improved with the incorporation of fibers. The flexural strength and flexural toughness of LDCC was found to increase from 26.8 pounds per square inch (psi) (0.18 MPa) to 217.5 psi (1.48 MPa), and from 5.67 lb-in. (0.64 kN-mm) to 292 lb-in. (33.0 kN-mm) respectively at a 1.0% addition rate of a fibrillated polypropylene fiber selected in this study, which makes it a feasible material for non-structural applications.

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