Expansion of Cement Mortar Mixing Expansive Agent under Different Curing Conditions and Compressive Strength in Constrained Conditions

2013 ◽  
Vol 405-408 ◽  
pp. 2534-2537 ◽  
Author(s):  
Yuan Yuan Wu ◽  
Yuan Peng ◽  
Yong Dao Liu ◽  
Li Li Jia
Keyword(s):  
Compressive Strength ◽  
Cement Mortar ◽  
Steel Tubes ◽  
Curing Conditions ◽  
Expansive Agent ◽  
Calcium Sulphoaluminate ◽  
Constrained Conditions ◽  
Concrete Filled Steel Tubes ◽  
Expansion Effect ◽  
Closed Environment

The expansion of cement mortar mixing expansive agent under standard curing and membrane curing conditions and compressive strength in constrained conditions are studied in this paper. Results show that the early expansion effect of calcium sulphoaluminate hydrate-calcium hydroxide expansive agent is obvious, mid-to late effect of magnesia expansive agent increase clearly. Compare with standard curing, the shrinkage of the basic cement mortar increase and expansion effect of expansive agent reduce under membrane curing. The expansion effect of expansive agent B is good and persistent under membrane curing, its applicable to used in the closed environment, such as concrete filled steel tubes. The compressive strength of mortar with expansion agent is a little more than the basic mortar under the condition of limit.

scholarly journals Experimental Study on Deformation Behavior and Compressive Strength of Concrete Cast in Steel Tube Arches under Low-Temperature Conditions

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Tuo Shi ◽  
Nianchun Deng ◽  
Xiao Guo ◽  
Wen Xu ◽  
Shi Wang
Keyword(s):  
Compressive Strength ◽  
Low Temperature ◽  
Performance Test ◽  
Large Diameter ◽  
Test Site ◽  
Steel Tube ◽  
Design Strength ◽  
Curing Conditions ◽  
Expansive Agent ◽  
Arch Bridges

Taking the construction of a concrete-filled steel tube (CFST) arch bridge (part of the Sichuan-Tibet Railway) in low temperatures as the test site, firstly the deformation performance test of concrete was carried out. Following this initial testing, measurement of compressive strength and shrinkage performance was conducted in large-diameter CFSTs under a variety of curing conditions. Experimental results showed that the expansion effect of Ca-Mg composite expansive agent in concrete was better than that of other expansive agents at any stage. Under low-temperature curing (0°C), the sampling strength of the large-diameter CFSTs reached 73.5% of the design strength at 28 d in the presence of a nonthermal curing system. The design strength itself was reached, when a curing system involving a thermal insulation film was applied, and use of this film also led to improvements in concrete shrinkage. The results suggested that a Ca-Mg composite expansive agent, combined with an insulation film curing system, should be the technique selected for concrete pumping construction of CFST arch bridges in Tibet.

Influences of Initial Curing Conditions on the Microstructure of Fly Ash Cement System

2010 ◽  
Vol 168-170 ◽  
pp. 532-536 ◽  
Author(s):  
Guo Li ◽  
En Li Lu ◽  
Peng Wang ◽  
Ou Geng ◽  
Yong Sheng Ji
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Cement Mortar ◽  
Early Age ◽  
Concrete Durability ◽  
Cement Concrete ◽  
Hydration Degree ◽  
Curing Conditions ◽  
Cement System ◽  
C 30

In order to study the influences of initial curing conditions on fly ash (FA) cement concrete durability, fly ash cement samples with 30% replacement ratio were fabricated and cured in water at 10°C, 20°C, 30°Cand 40°C for 3d, 7d, 14d and 28d respectively. Hydration degrees of fly ash at early age were measured using the selective dissolve method. Correspondingly the pore structure and morphology of FA-cement mortar and compared cement mortar were studied by using MIP and SEM methods. Then early age compressive strengths of FA-cement concrete and compared normal cement concrete were tested. Experimental results show that initial curing temperatures and ages are important factors to fly ash early age hydration degree, FA-cement system microstructure, morphology and early age compressive strength etc. High curing temperatures and longer curing time can lead higher fly ash hydration degree, and then higher compressive strength of FA-cement concrete, and make the micro-structures of fly ash-cement system denser.

Experimental Study of Performance of Self-Stress Lightweight Aggregate Concrete Filled Steel Tubes after Exposure to Fire

2013 ◽  
Vol 790 ◽  
pp. 173-176
Author(s):  
Jin Can Xu ◽  
Peng Fei Ren ◽  
Hai Lun Tong ◽  
Xin Tang Wang
Keyword(s):  
Bearing Capacity ◽  
Fire Behavior ◽  
Lightweight Aggregate ◽  
Lightweight Aggregate Concrete ◽  
Fire Load ◽  
Steel Tubes ◽  
Aggregate Concrete ◽  
Expansive Agent ◽  
Short Columns ◽  
Concrete Filled Steel Tubes

The post-fire behavior of a set of self-stress lightweight aggregate concrete filled steel tubular short columns (noted as SSLC-SSC) after exposure to fire was experimentally studied. Effect of the maximum value of fire response temperatures of the tubes and their geometric parameters on the strength and the other mechanical property of the specimens were especially discussed. The experimental results show that the specimens of SSLC-SSC have higher post-fire bearing capacity and better plastic deformation, there was no obvious descent segment in post-fire load-displacement curves of the most specimens subjected to fire load. It was concluded that the maximum response temperature of specimens has great effect on the post-fire bearing capacity of self-stress concrete-filled steel tubes subjected to fire load, and the value of self-stress corresponding to 10% of dosage of expansive agent has the greatest effect on post-fire bearing capacity of specimens of SSLC-SSC.

scholarly journals Numerical Study of Circular Concrete Filled Steel Tubes Subjected to Pure Torsion

Buildings ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 397
Author(s):  
Khanh Ba Le ◽  
Vui Van Cao
Keyword(s):  
Compressive Strength ◽  
Parametric Study ◽  
Numerical Study ◽  
Steel Tube ◽  
Torsional Moment ◽  
Pure Torsion ◽  
Steel Tubes ◽  
Moment Capacity ◽  
Compressive Strength Of Concrete ◽  
Concrete Filled Steel Tubes

This study numerically explored the torsional behavior of circular concrete-filled steel tubes (CFST) under pure torsion. Numerical models of CFSTs were developed in ABAQUS. The models were validated by comparing with the experimental results available in the literature; then, these models were used for parametric study. Based on the obtained results, the mechanism of torsional moment transferring from steel plates to CFST was presented. The results obtained from the parametric study indicated that the compressive strength of concrete marginally improved the torsional moment capacity of the CFST while concrete prevented buckling and helped the steel tubes to work more effectively. The steel strength significantly affected the torsional moment capacity of the CFST. When the yield strength of steel increased from 235 to 420 MPa, the yield torsional moment of the CFST increased by approximately 50%. The yield torsional moment capacity of the steel tube had the strongest correlation with the yield moment of the CFST, followed by the ratio of diameter to thickness of the steel tube while the parameters related to the compressive strength of concrete exhibited a poor correlation with the yield torsional moment.

scholarly journals Experimental Behavior of Composite Infilled & Encased Column by using MSAND, Metakaolin & Recron Fibre

2019 ◽  
Vol 8 (4) ◽  
pp. 12508-12514
Keyword(s):  
Compressive Strength ◽  
Cross Section ◽  
Load Carrying Capacity ◽  
Steel Tubes ◽  
Circular Section ◽  
Concrete Filled Tubes ◽  
Load Carrying ◽  
Fiber Concrete ◽  
Infill Material ◽  
Concrete Filled Steel Tubes

In this analysis, take a look at on compressive strength of composite infilled and encased columns were done. Compressive strength of hollow, tubular and encased typical section in addition as Msand, silcafume, metakaolin & recorn fiber concrete-filled tubes were decided. Cross-section, compressive strength, and mode of failure of the column to be explored. The circular section and square section were selected for this research. The association between the load, and the later displacement at the mid-tallness, base, and top of the sections inside the bearing of each the durable and powerless axes, and furthermore the connections of burden versus complete the process of shortening for each example was reliably recorded. It completely was discovered that the load carrying limit differs with importance to the cross-section of the specimen, compressive strength of the infill material. The investigation is carried out for the water-cement ratio of 0.5% for in composite column of size 150 × 150 × 1800 mm and diameter of 1800 mm of square and circular section. Then the specimens are to be tested on 7th day, 14th day and 28th day. The circular specimens having higher load-carrying capacity than square specimens. Msand, metakaolin and recron fiber waterproof agent concrete infilled in and encased steel tubes show 5% to 15 % more strength than typical control concrete-filled steel tubes.

scholarly journals Influence of Curing Conditions on Strength Characteristics of Sea Sand Mortar

2021 ◽  
Vol 7 (2) ◽  
pp. 160
Author(s):  
Irka Tangke Datu ◽  
Adiwijaya Ali ◽  
Nur Aisyah Jalali ◽  
Khairil Khairil
Keyword(s):  
Compressive Strength ◽  
Cement Mortar ◽  
Tap Water ◽  
Strength Characteristics ◽  
Fine Aggregate ◽  
River Sand ◽  
Strength Performance ◽  
Curing Conditions ◽  
Water Characteristics ◽  
Sea Sand

This present paper aims to investigate strength characteristics of cement mortar using natural sea sand as fine aggregate in different curing conditions. Research was carried out with making mortar mixtures by two types of cement, Portland Composite Cement (PCC) and Pozzolana Portland Cement (PPC) with tap water as mixing water. Characteristics of fine aggregate and strength of cement mortar use river sand (RS), sea sand (SS), and washed sea sand (WS) were observed. Further, specimens of cube mortar in size of 50 mm x 50 mm x 50 mm of six mortar mixture series were casted according to Indonesian Standard. At 24 hours after cube specimens were casted, cube mortar specimens were cured in three curing conditions such as tap water curing (TC), seawater curing (SC) and air curing (AC). After curing at certain period (3-day, 7-day, 14-day, and 28-day), cube mortar samples were tested in compressive strength. Results concluded that sea sand aggregate improve characteristic of mortar in compressive strength up to 28 days in all curing conditions, and there was no significant effect of type of curing water (TC and SC) on 28-day strength performance of mortar was obtained. In addition, sea sand could potentially be utilized as an aggregate in production of mortar and/or concrete.

Evaluation of effects of multi-varied atmospheric curing conditions on compressive strength of bacterial (bacillus subtilis) cement mortar

2019 ◽  
Vol 218 ◽  
pp. 1-7 ◽  
Author(s):  
Muyideen Abdulkareem ◽  
Fadeelat Ayeronfe ◽  
Muhd Zaimi Abd Majid ◽  
Abdul Rahman Mohd.Sam ◽  
Jang-Ho Jay Kim
Keyword(s):  
Compressive Strength ◽  
Bacillus Subtilis ◽  
Cement Mortar ◽  
Curing Conditions

Incorporation of Iraqi Rocks in the Production of Eco-Friendly Cement Mortar

2020 ◽  
Vol 38 (10A) ◽  
pp. 1522-1530
Author(s):  
Rawnaq S. Mahdi ◽  
Aseel B. AL-Zubidi ◽  
Hassan N. Hashim
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Compressive Strength ◽  
Water Absorption ◽  
Structural Properties ◽  
Mechanical Milling ◽  
Cement Mortar ◽  
Cement Mortars

This work reports on the incorporation of Flint and Kaolin rocks powders in the cement mortar in an attempt to improve its mechanical properties and produce an eco-friendly mortar. Flint and Kaolin powders are prepared by dry mechanical milling. The two powders are added separately to the mortars substituting cement partially. The two powders are found to improve the mechanical properties of the mortars. Hardness and compressive strength are found to increase with the increase of powders constituents in the cement mortars. In addition, the two powders affect water absorption and thermal conductivity of the mortar specimens which are desirable for construction applications. Kaolin is found to have a greater effect on the mechanical properties, water absorption, and thermal conductivity of the mortars than Flint. This behavior is discussed and analyzed based on the compositional and structural properties of the rocks powders.

scholarly journals Mechanical Behavior of Brick Masonry in an Acidic Atmospheric Environment

Materials ◽  
2019 ◽  
Vol 12 (17) ◽  
pp. 2694 ◽  
Author(s):  
Shansuo Zheng ◽  
Lihua Niu ◽  
Pei Pei ◽  
Jinqi Dong
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Fly Ash ◽  
Acid Rain ◽  
Cement Mortar ◽  
Brick Masonry ◽  
Atmospheric Environment ◽  
Peak Strain ◽  
Lime Mortar ◽  
Attenuation Model

In order to evaluate the deterioration regularity for the mechanical properties of brick masonry due to acid rain corrosion, a series of mechanical property tests for mortars, bricks, shear prisms, and compressive prisms after acid rain corrosion were conducted. The apparent morphology and the compressive strength of the masonry materials (cement mortar, cement-lime mortar, cement-fly ash mortar, and brick), the shear behavior of the masonry, and the compression behavior of the masonry were analyzed. The resistance of acid rain corrosion for the cement-lime mortar prisms was the worst, and the incorporation of fly ash into the cement mortar did not improve the acid rain corrosion resistance. The effect of the acid rain corrosion damage on the mechanical properties for the brick was significant. With an increasing number of acid rain corrosion cycles, the compressive strength of the mortar prisms, and the shear and compressive strengths of the brick masonry first increased and then decreased. The peak stress first increased and then decreased whereas the peak strain gradually increased. The slope of the stress-strain curve for the compression prisms gradually decreased. Furthermore, a mathematical degradation model for the compressive strength of the masonry material (cement mortar, cement-lime mortar, cement-fly ash mortar, and brick), as well as the shear strength attenuation model and the compressive strength attenuation model of brick masonry after acid rain corrosion were proposed.

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