Alex Mrema

9 Questions 23 Answers 0 Followers

Questions related from Alex Mrema

How do we get rid of the pollution problems of waste polythene bags?

The use of polythene bags in packaging is a major cause of pollution. These bags cause environmental problems if they are not properly disposed of. One method to get rid of them is to recycle them...

30 July 2018 7,926 7 View

Construction in sea water. Why are pozzolanic and slag cements recommended?

Can someone explain why pozzolanic/slag cements prove more resistant to corrosion than other cements in constructions in the sea.

06 April 2018 1,767 6 View

Why do we insist in using standard sand in cement strength tests when we can use locally blended sands?

Importing standard sand for cement tests is becoming unnecessarily expensive. Why can't we use local sands which have been blended to approximate the grading of the 'standard sand'. Would there be...

06 November 2017 6,836 8 View

What is the effect of mixing gypsum with white cement?

I have specified gypsum plaster for internal walls of a building and white cement for the external walls. Is there any consequences if the white cement is accidentally mixed with small amounts of...

01 November 2017 5,896 15 View

Why are the desorption and adsorption curves for timber different?

When studying the sorption for timber at 20 deg. C and one plots the equilibrium moisture content in volume % against the relative humidity of the surrounding air from 0% to 100% relative humidity...

09 August 2016 6,063 2 View

How can the direct tensile test for concrete be done in a laboratory environment?

I have a problem of a test setup to do the direct tensile test in a universal testing machine. The machine jaws cannot be applied directly to grip the test specimens because of local damage and...

27 May 2016 1,033 8 View

How can I estimate the maximum temperature reached in a concrete building that was gutted by fire?

I am investigating on the effect of a fire that gutted a concrete building. I am determining the residual strengths of the structural and building elements after the fire. Is there a way of...

26 May 2016 5,317 8 View

Is it of any cosequence if a bit of OPC is added to a mortar made of rice husk ash and lime as a binder?

I am trying to find an optimum mix proportion for a rice husk ash - hydrated lime binder to be used with sand in the making of a building mortar. The pH of the mortar is around 12.6. Can I speed...

07 April 2016 6,060 4 View

What is the optimum water cement ratio for maximum strength in a sand cement block?

The bulk density of sand varies with moisture content and is minimum at about 5% moisture content. At this moisture content of about 5%, the surface tension of the water film around the particles...

23 July 2015 4,254 12 View