Effect of added the polycarboxylate ether on slump retention and compressive strength of the high-performance concrete

Abstract

It is well known that workability of high performance concrete (HPC) is dependent on slump value of concrete mixture. Moreover, slump retention is the most sensitive compared to a well-known slump value because it represents the durability of concrete mixture for its applications in the field of civil engineering. This research used the polycarboxylate ether (PCE) to increase slump value of concrete mixture and then verified the effect of PCE on the slump retention and compressive strength of different high-performance concretes. 0%, 0.5%, 1%, 2% of PCE were added into concrete mixture to yield a minimum compressive strength of f’c 50 MPa. The slump retention tests were performed at 0, 15, 30, 45, 60 and 75 minutes while the compressive strength tests were carried out at 3, 7, 14 and 28 days for every concrete sample. The result findings showed that the optimal concrete performance can be achieved by adding 2% of PCE to reach at a slump retention value of 45 minutes and a compressive strength of 53.84 MPa. Effect of PCE on the slump retention and compressive strength has been verified to contribute an insight into the application of a proper designed workability of HPC.

Computational-experimental method for determining the height of steel fiber sedimentation in Ultra-High Performance Self-Compacting Concrete

“…During the hydration of Portland cement, CSH gel on the surface of the grains overlap the side chains of polycarboxylate molecules. If there is a reserve of non-adsorbed molecules in the water surrounding the particles, they will be adsorbed on the hydration products, which is visually expressed in greater preservation of the properties of the concrete mixture [20]. At high dosages of the additive, a larger reserve of not yet adsorbed molecules remains in the pore space, as a result of which the viscosity of the mixture increases more slowly, allowing the fiber to move a greater distance under the influence of gravity.…”

“…The coefficient K will be equal to the ratio of the actual volume content of the fiber in the upper and lower parts of the product: If К = 𝐾𝐾 𝑐𝑐𝑐𝑐 (equation 15), then formula 19 will look like this: 𝐻𝐻 𝑠𝑠𝑠𝑠𝑠𝑠,𝑐𝑐𝑐𝑐 = 0,036 • 𝐻𝐻 𝑠𝑠𝑠𝑠𝑠𝑠𝑐𝑐 (20) The resulting equations can be used in the selection of concrete composition. To do this, the critical sedimentation height of the fiber 𝐻𝐻 𝑠𝑠𝑠𝑠𝑠𝑠,𝑐𝑐𝑐𝑐 is first calculated using formula 20.…”

Comparative of the Use of Carbon and Steel Fiber to the Mechanical Properties of Self Compacting Concrete

“…Carbon Reinforced Polymer (CFRP) has the advantage of having higher strength, a low weight, high stiffness, corrosion resistance, lower maintenance costs and faster installation time [10] SCC Mix Design refers to previous studies [11]. However, modifications were made with the addition of a water volume of 4.9% and PCE type super plasticizer of 3.1%, which is capable of increasing concrete compressive strength by 26.77% [12].…”