Residual TRM-to-Concrete Bond after Freeze–Thaw Cycles

In the present work, the effect of various freeze–thaw cycles (namely, 0, 10, 30, 50, 60, and 70) on the residual bond characteristics of textile reinforced mortar (TRM)-to-concrete was experimentally examined. The TRM consisted of a carbon dry fiber textile embedded in a cement-based matrix. Two mortar types were used as the matrix: a normal-weight and a lightweight one sharing the same hydraulic powders but different aggregates (limestone and pumice sand, respectively). The single-lap/single-prism set up was applied after the specimens underwent hygro-thermal treatment (according to ASTM C 666-Procedure B). Failure was due to the sleeve fibers rupturing the load aligned yarns or textile slippage from the mortar for an exposure period ranging between 0 and 60 cycles and to TRM debonding from the substrate for 70 cycles. Increasing cycles resulted in the intensification of partial interlaminar debonding phenomena and the weakening of the textile-to-matrix bond, with lightweight mortar being more prone to these effects. In the absence of a commonly accepted standardized method for the assessment of the freeze–thaw resistance of cement-based composites, the criterion for the termination of the freeze–thaw sequence was the number of cycles inferring a shift in failure mode (from fiber rupture/fiber slippage to TRM debonding from the substrate).

Durability of Normal and Lightweight Aggregate Mortars with Different Supplementary Cementitious Materials

A study on the durability parameters of normal and lightweight aggregate mortars, incorporated different supplementary cementitious materials (SCM) is presented. Mortars were prepared using limestone or pumice as aggregates and Metakaolin, Fly ash, Granulated Blast Furnace Slag and Silica Fume, as SCM, that they replaced cement, at 10 % by mass. Ten different mortars, having same water to binder ratio and aggregate to cement volumetric ratio, they were compared mainly in terms of durability. The use of pumice sand was proved to be effective not only to the density of the mortars as it was expected, but also in durability, fulfilling at the same time minimum strength requirements. The addition of the different SCM further enhanced the durability of the mortars, where Metakaolin was found to be the most effective one, especially against chloride’s ingress.

Comparison of Compressive Strength Value of Concrete Using Pumice Sand with Ordinary Sand as Fine Aggregate

In this study, the method according to the Indonesian National Standard (SNI) was applied. The objects test in the form of cylindrical concrete in which the fine aggregate was pumice sand and ordinary sand. The test objects made were tested for compressive strength. There were 6 test objects made in this study with a size of 15 cm x 30 cm. In detail, 3 test objects were made of pumice sand, while the other 3 test objects were made of ordinary sand. The coarse aggregate for all test objects was crushed stone. The result shown the use of pumice sand as a substitute for fine aggregate can reduce the compressive strength of concrete by 23.53%. However, it can reduce the weight of concrete by 7.03%. Therefore, for construction that prioritizes weight, concrete with pumice sand as fine aggregate is better compared to concreate with ordinary sand as fine aggregate.

Experimental Study of the Use of Pumice Sand in the Rigid Pavement

The Pumice sand is a bright colored butian type, containing foam made from glass-walled bubbles and usually referred to as silicate volcanic glass granules. This pumice sand can be used as a substitute for normal sand as fine aggregate in a mixture of concrete mix. Based on the characteristic test examination, it can be seen that in testing the characteristics of pumice sand to the specifications of normal sand in specific gravity testing and weight testing of quicksand obtained results that are smaller than the specifications of normal sand and absorption tests obtained results greater than specifications on normal sand. The results of the normal sand compressive strength at BN is 250.95 kg /cm2 while the results of the floating sand concrete compressive strength on BPA is 224, 965 kg /cm2. Based on the research it can be concluded that with the same quality of concrete, the quality of K-250 is different in comparison to the compressive strength of concrete in normal sand and pumice sand concrete shows almost the same results. Therefore, more in-depth research is needed regarding the use of pumice sand instead of normal sand in a mixture of concrete mix

Manufacturing and Characterization Process of Polymer Concrete with Aggregate From Pumice Stone and Corn Husk Fiber as A Filler

Research has been carried out regarding the manufacturing process of polymer concrete made from a mixture of pumice, sand (1: 1), corn husk fiber, epoxy and thinner resin. This research was conducted to determine the characterization of polymer concrete which will be tested physically and mechanically with the best composition mixture. The physical properties of polymer concrete which were analyzed namely density, porosity and water absorption; mechanical properties including impact strength, flexural strength and compressive strength, and polymer concrete microstructure analysis, namely SEM-EDX. The best results were obtained with a mixture of pumice, sand (1:1), corn husk fiber, epoxy and thinner resin. The result are as stated here, density: 1.84 g/cm3 with composition (49:49:2) 30 g epoxy resin, porosity : 0.44% with composition (50:50:0) 20 g epoxy resin, water absorption: 1.8% with composition (50:50:0) 25 g of epoxy resin. Whereas mechanical properties, on impact tests: 4.956 KJ/m2 with composition of (47:47:6) 25 g epoxy resin, flexural test: 22.22 MPa with composition of (45:45:0) 30 g epoxy resin, pressure test: 8.41 MPa with composition of (49:49:2) 30 g epoxy resin. XRD analysis shows that each of its constituents still have quartz, pumice, quartz, pumice-shaped hexagonal crystals, while corn husk fibers are amorphous crystals. The average sound absorption coefficient for the three samples (20%, 25%, and 30%) are 0.178; 0.152; and 0.234 at a frequency of 500 Hz - 6300 Hz, which meets the requirements of ISO 11654 and ASTM C.384.

ANALISA KUAT TEKAN BETON MENGGUNAKAN PASIR APUNG

Pumice sand is a bright colored butian type, containing foam made from glass-walled bubbles andusually referred to as silicate volcanic glass granules. This pumice sand can be used as a substitutefor normal sand as fine aggregate in a mixture of concrete mix. Based on the characteristic testexamination, it can be seen that in testing the characteristics of pumice sand to the specificationsof normal sand in specific gravity testing and weight testing of quicksand obtained results thatare smaller than the specifications of normal sand and absorption tests obtained results greaterthan specifications on normal sand. The results of the normal sand compressive strength at BN is250.95 kg /cm2 while the results of the floating sand concrete compressive strength on BPA is224, 965 kg /cm2. Based on the research it can be concluded that with the same quality of concrete,the quality of K-250 is different in comparison to the compressive strength of concrete in normalsand and pumice sand concrete shows almost the same results. Therefore, more in-depth researchis needed regarding the use of pumice sand instead of normal sand in a mixture of concrete mix.